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We aimed to clarify the acute effects of mild exercise on cold sensory function and brain activity of women with a cold constitution (called hie-sho in Japanese). Eight cold-sensitive young women (C group) and eight normal young women (N group) performed cycle exercise with a lieht-to-moderate intensity for 15 min with eye closure at a room temperature of 25° C. Electroencephalography (EEG), sublingual temperature (Tsl) and skin temperature (Tsk) at 10 sites, and thermal sensation in 11 regions were measured. Before initiating exercise, cold sensation in the extremities of limbs was higher (p < 0.05) in the C group than the N group. Significant increases in Tsl and Tsk immediately after exercise were found in participants with reduced cold sensation. EEG alpha wave power was consistently lower (p < 0.05) in the C group than the N group throughout the experiments; however, no changes in spectral power by executing exercise were found. In the two groups, beta wave power was increased (p < 0.05) during exercise at moderate intensity (~60% of maximum), which promptly returned to pre-exercise levels after exercise. These findings suggest that performing a single dynamic exercise inhibits cold sensation due to thermal effects of exercise without altering alpha wave and beta wave power during rest under normal temperature conditions in cold-sensitive women. [ABSTRACT FROM AUTHOR]

Background: We examined whether an aerobic exercise intervention in young women with cold sensitivity symptoms improves sleep quality and decreases cold complaints. Furthermore, we examined the association with increased foot skin temperature (Tsk) before falling asleep and decrease in sensitivity to cold in the brain. Methods: We recruited 16 female adult volunteers who had cold sensitivity and were not engaged in daily exercise training, and they were divided into an exercise group (EXE) and a control group (CON). EXE was given a 2-week exercise intervention that consisted mainly of walking and jogging. Before and after the intervention, temperature sensation and body temperature parameters were measured just before bedtime; electroencephalogram measurements were taken during sleep; and subjective sleep surveys, including Oguri-Shirakawa-Azumi (OSA) sleep inventory (middle-aged and aged version) and visual analogue scale (VAS), were conducted immediately after waking up. All experiments were performed in the winter season. Results: In EXE, overall and foot warmth and comfort increased (p < 0.05) after the 2-week exercise intervention. The exercise intervention also decreased (p < 0.05) the scores for cold feeling in the fingertips, feet, and toes. In the OSA sleep inventory, factor IV (refreshing) and factor V (sleep length) were increased (p < 0.05) by the exercise intervention. Subjective sleep quality evaluated by VAS increased (p < 0.05) with exercise intervention. The exercise intervention in EXE shortened middle awake time after sleep onset (p < 0.05) and prolonged deep sleep length (p < 0.05). The exercise intervention increased (p < 0.05) alpha-wave power before sleep. In CON, all variables remained unchanged throughout the 2-week control period. Conclusion: Short-term aerobic exercise alleviated peripheral extremity cold sensitivity symptoms and improved subjective sleep quality. Our findings suggest that these improvements were not due to increased Tsk at rest before bedtime but to decreased sensitivity to cold in the brain that was expressed as increased alpha activity. [ABSTRACT FROM AUTHOR]

In recent years, the study of thermal comfort has gained significant attention for its profound impact on human well-being and productivity. Addressing thermal comfort in healthcare environments has become increasingly important as public demand for improved healthcare standards increases and patients prioritize their overall experience during medical visits. This study explores advances in thermal comfort research in healthcare facilities, tailored to the specific characteristics of Chinese healthcare facilities. It covers various aspects, including China's five major climatic regions, different categories of healthcare facilities, distinct functional zones within healthcare facilities, and different demographic groups. Additionally, this study summarized thermal sensation data across diverse demographic groups from reviewed literature, analyzing median indicators of different groups. When compared with current standards, it appears that while these standards generally support the broad needs of healthcare facility occupants, they fall short of accommodating the detailed design requirements specific to environments of healthcare facilities. The study identifies shortcomings in domestic research and suggests future research directions. It provides valuable insights for optimizing healthcare facilities' designs and environmental parameters in accordance with evolving global standards in healthcare facility management in China. • Predominant research in the HSCW zone reveals gaps in other Chinese climatic regions. • Class 3 A hospitals are the main focus, with fewer studies on primary care. • Inpatient departments are well-studied, but other departments need more research. • Less comprehensive research on thermal comfort for staff and visitors. • Current standards meet broad needs but lack specificity for special populations. [ABSTRACT FROM AUTHOR]

Understanding how long-term thermal history affects thermal comfort expectations in older adults (65+) has implications for designing energy-efficient spaces in a changing climate. A growing number of studies focus on thermal sensation/preference votes to represent the current thermal comfort expectations, often overlooking their limitations. This study, however, investigates how factors shaping long-term thermal history link to the current 65+ adults indoor thermal comfort expectations during exposure to heat, by focusing on the upper limit of thermally acceptable temperature range, represented by a self-reported temperature threshold at which 65+ adults believe to feel uncomfortable by indoor heat (T it). To find T it , we use answers to " Above what temperature do you start feeling too hot indoors? " by survey respondents in Warsaw (n = 678) and Madrid (n = 527), who lived in their apartment ≥5 years. Statistically, we find indoor factors affecting long-term thermal experiences more significant in explaining 65+ T it , when compared to outdoor factors such as distance to water, vegetation, or surface thermal radiance. Better-insulated buildings were associated with a lower T it (p < 0.05), suggesting a higher thermal sensitivity of such building residents to heat. Our key findings indicate for normal housing units' area (∼80 m2), personal factors such as Basal Metabolic Rate (main effect 95% CI = +0.42 – +2.6 °C) and health status (+0.11 – +1.68 °C) were associated with a higher 65+ T it and lower thermal sensitivities to heat (p < 0.05). Findings shed light on the complexity of factors shaping indoor thermal comfort expectations among 65+ adults. • Building, environmental, socio-economic, and demographic factors are considered. • Better building insulation is linked to an increased thermal sensitivity to heat. • A high Basal Metabolism Rate correlates with a reduced thermal sensitivity to heat. • Better Health Status correlates with a reduced thermal sensitivity to heat. • Factors affecting indoor thermal experiences are more significant than outdoor ones. [ABSTRACT FROM AUTHOR]

This review mainly aimed to introduce the findings of research projects comparing the responses of tropical and temperate indigenes to heat. From a questionnaire survey on thermal sensation and comfort of Indonesians and Japanese, we found that the thermal descriptor "cool" in tropical indigenes connotes a thermally comfortable feeling, suggesting that linguistic heat acclimatization exists on a cognitive level. Ten male students born and raised in Malaysia were invited to Fukuoka, Japan, and compared their responses with 10 Japanese male students with matched physical fitness and morphological characteristics. Cutaneous thermal sensitivity: The sensitivities were measured at 28 °C. The forehead warm sensitivity was significantly blunted in Malaysians. The less sensitivity to the warmth of tropical indigenes is advantageous in respect to withstanding heat stress with less discomfort and a greater ability to work in hot climates. Passive heat stress: Thermoregulatory responses, especially sweating, were investigated, during the lower leg hot bathing (42 °C for 60 min). The rectal temperature at rest was higher in Malaysians and increased smaller during immersion. There was no significant difference in the total amount of sweating between the two groups, while the local sweating on the forehead and thighs was lesser in Malaysians, suggesting distribution of sweating was different from Japanese. Exercise: Malaysian showed a significantly smaller increase in their rectal temperature during 55% maximal exercise for 60 min in heat (32 °C 70% relative humidity), even with a similar sweating and skin blood flow response in Japanese. The better heat tolerance in Malaysians could be explained by the greater convective heat transfer from the body core to the skin due to the greater core-to-skin temperature gradient. In addition, when they were hydrated, Malaysian participants showed better body fluid regulation with smaller reduction in plasma volume at the end of the exercise compared to the non-hydrated condition, whereas Japanese showed no difference between hydration conditions. We further investigated the de-acclimatization of heat adaptation by longitudinal observation on the heat tolerance of international students who had moved from tropical areas to Fukuoka for several years. [ABSTRACT FROM AUTHOR]

Thermal comfort models that account for individual thermal sensations are crucial for optimizing environmental control while maintaining occupant comfort. However, the current approach of developing occupant-specific models is not scalable for new occupants whose data were not used for training, making it impractical for multi-occupant spaces and burdensome for management. To address this, we propose a thermal comfort model based on a subject-independent evaluation approach, capable of generalizing to new individuals not included during model training. This model accurately predicts thermal sensations without the need for occupant-specific models, allowing scalability and adaptability to new occupants. Furthermore, this study considers occupants with face masks, which is essential in environments where masks are required for their wellbeing and performance. The model was developed using Compact Convolutional Transformers which combines convolutional layers and transformer layers, allowing the model to capture both fine-grained local features and broader contextual relationships, making it effective for predicting thermal comfort from thermal images. The model was trained using the Leave-One-Subject-Out (LOSO) and Leave-One-Group-Out (LOGO) training approaches. The LOSO approach achieved high accuracies of 98.04 %, 98.93 %, and 98.88 % for dataset A (participants without face masks), dataset B (participants with face masks), and dataset C (a combination of both), respectively. The LOGO approach achieved accuracies of 99.92 %, 99.40 %, and 99.85 % for datasets A, B, and C, respectively, showing a slightly better prediction performance. The approach presented in this study offers a promising solution for designing accurate generalized models for real-time environmental control to meet the thermal comfort needs of occupants. • Generalized comfort models were developed using thermal images and transformer. • Data was collected from 19 participants under varying temperature conditions. • Models predict thermal comfort with 98–99 % accuracy, with or without face mask. • Leave-one-group-out training captures occupants' thermal responses better. [ABSTRACT FROM AUTHOR]

Skin temperature is a widely used physiological parameter in thermal comfort research. It serves as an indicator of personnel's thermal comfort and has the potential to guide the regulation of thermal conditions in future indoor environment designs. This study reviews relevant publications from 2013 to late 2023, focusing on population differences in skin temperature (local characteristics, age, gender, etc.), changing characteristics in different environments (dynamic and non-uniform environment, sleep environment, outdoor environment, etc.), and the application of skin temperature in thermal sensation prediction and performance evaluation of devices. This study clarifies the effectiveness of skin temperature in characterizing the thermal state of the human body through a review of existing research. It also proposes directions for future work considering research limitations in personal comfort models and performance evaluation of devices. The study suggests that skin temperature is likely to play a significant role in the future due to the development of technologies such as big data and the Internet of Things. In addition to conducting in-depth research in subdivided fields based on existing research, it is also important to pay attention to standardized data collection and processing. [Display omitted] [ABSTRACT FROM AUTHOR]

Various individual thermal preferences do not always lead to optimal thermal comfort, despite the high energy consumption of Heating, Ventilation, and Air Conditioning (HVAC) systems. Thermal comfort models often struggle to accurately predict occupants' thermal sensations due to their inability to adapt to diverse scenarios. This research employs machine learning techniques to develop personalized data-driven thermal comfort models using a global database of 17,814 samples from the ASHRAE Global Thermal Comfort Database II. Specifically, the study implements random forest and k-nearest neighbor algorithms to analyze the influence of environmental factors (such as air temperature, outdoor temperature, relative humidity, and air velocity) and personal factors (including clothing insulation, activity level, and individual differences) on thermal comfort perception. The study systematically compares the predictive performance of different output types (thermal sensation vs. preference vote), input parameters (6 vs. 12), and machine learning methods. The optimized random forest model with 12 inputs demonstrated an accuracy of over 70% in predicting thermal preference votes, which was significantly higher than the 34% accuracy of the PMV model. The results present new optimized data-driven models and offer insights into the relative influence of parameters such as climate, building cooling strategies, and occupant age and gender. This research aims to enable personalized thermal comfort predictions to improve satisfaction and energy efficiency in various buildings. • Developing extensive and accurate models to predict personalized thermal comfort. • Systematic evaluation of algorithms, inputs, and outputs to optimize predictors. • Employing hierarchical feature selection to find the optimal set of mixed features. • Providing a framework for developing accurate, practical, and adaptable models. [ABSTRACT FROM AUTHOR]

To improve the cabin thermal environment and explore advanced automotive air-conditioning control methods, it is essential to understand the key factors affecting occupant thermal response as well as the synchronicity of the thermal response to environmental changes in outdoor conditions. Given the current gaps in research, this study conducted outdoor experiments in summer to analyze the correlation and synchronicity between the cabin thermal environment and occupant thermal sensation as well as facial skin temperature. Results showed that, during the cooling phases of experiments with high initial cabin air temperatures, occupant thermal sensation improved significantly within 7 min. After 15 min, facial skin temperature and thermal sensation reached quasi-steady states. Thermal sensation was primarily influenced by air temperature, followed by solar radiation, and exhibited significant synchronicity with changes in these factors. When the air temperature stabilized at around 26 °C, every 200 W/m2 of solar radiation exposure increased the thermal sensation unit during the 40-min experiment period. Cheek and nose skin temperatures were significantly correlated with air temperature and solar radiation, and were sensitive to environmental changes, synchronizing with changes in air temperature and relative humidity. Further analysis showed the feasibility of using cheek and nose skin temperatures to characterize the occupant thermal sensation in a cabin. Additionally, this study found sex differences in the occupant thermal response in a cabin. The results provide insight into the key optimization parameters for comfort-oriented cabin thermal environment design and offer support for future air conditioning control in cabins based on thermal imaging. [Display omitted] • Evidence for assessing thermal sensation using cheek and nose temperature in cabin • Facial temperatures are sensitive to changes in air temperature and relative humidity • Thermal sensation is mainly affected by air temperature, followed by solar radiation [ABSTRACT FROM AUTHOR]

It is crucial to investigate the effects of indoor thermal environmental conditions on human performance, especially in India, during the winter when there is a significant need for space heating to maintain human comfort conditions. The present study was conducted in a controlled climate during winter, with 96 participants exposed to four air temperatures: 15 °C, 18 °C, 21 °C, and 24 °C. Participant's thermal comfort, emotion, and self-rated workload were assessed using a subjective questionnaire, while their performance was quantitatively evaluated using a neurobehavioral test. The data was analyzed to establish how the various thermal environmental factors influence performance, workload, emotion, and thermal sensations. The results show that the highest performance within the experimental thermal environmental conditions was observed when the thermal sensation ranges from neutral to slightly warm (+0.20) at the 23.5 °C mean standard effective temperature. At the same sensation, the occupant's mood disturbance and the mental workload for completing the task were minimal. These results would be helpful for facility managers of buildings by giving them insight into the impact of under or over-heating spaces on occupant performance during winter in the composite climate of India. • Different thermal environmental conditions were maintained in a lab during winter. • A subjective questionnaire and neurobehavior approach were used for assessment. • Optimum performance was obtained at 23.5 °C mean standard effective temperature. • Minimum workload demand at optimum performance. • Total mood disturbance was minimal at optimum performance. [ABSTRACT FROM AUTHOR]

Assessing cabin occupants' thermal sensation in real-time enables automatic control of car air conditioning, improving driving safety and energy efficiency. Traditional methods, limited by their need for numerous physiological parameters, have restricted practicality. For this purpose, this study employs a low-cost thermal imaging sensor as the hardware core to establish a cost-effective and non-contact real-time assessment system for the thermal comfort of occupants within a cabin. The system comprises a thermal sensation assessment model developed based on subject experiments, along with facial recognition and segmentation algorithms optimized for thermal images. The thermal sensation assessment model developed, which employs cheek temperature, solar radiation intensity, and cabin air temperature as its features, exhibited an R2 of 0.617 on the test set. Furthermore, the facial recognition algorithm established for thermographic imaging achieved a mean accuracy of 96.5% and a recall rate of 99.0%. The system underwent validation in real-world vehicle environments, proving its ability to accurately detect and measure the cheek temperatures of occupants in the cabin and execute thermal sensation assessments. With a mean absolute error of 0.5 thermal sensation units in its output, its accuracy in practical applications was affirmed. This research provides an effective solution for automatically adjusting cabin air conditioning. • Developed a non-contact thermal sensation assessment system for cabin occupants. • Output of system can drive automatic controls for cabin air conditioner in the future. • Developed a simple thermal sensation assessment model for cabin, with an R2 of 0.617 • Developed facial region segmentation algorithm for low-resolution thermal imaging. • Established system validated with a mean absolute error of 0.49, showing high accuracy. [ABSTRACT FROM AUTHOR]

Exposure to extremely low-temperature building environments around −20 °C causes various hazards to human health. However, few studies have studied human thermal comfort and physiological response in such environments, nor the personal comfort heating system. Thus, this study investigated the heating characteristics of personal comfort heating system and their effects on thermal responses and thermophysiological parameters in extremely low-temperature building environments. We conducted experimental tests and questionnaires in a cryogenic enthalpy difference laboratory with air temperature ranging from −21.2 to −15.6 °C and a relative humidity of 55 %. Eight experimental conditions were designed with several heating measures (heating mat, heating gloves, heating cushion and airwarmer). The heating parameters of the personal comfort heating systems as well as the subjective evaluations and skin temperature of the subjects were recorded and analyzed. The results showed that the airwarmer confinement box condition had a corrective power of up to 38.3 K. The overall thermal sensation vote and overall thermal comfort vote were maintained at 0.25 and −0.25. Further, we found that the face, hands, calves and feet got cold easier with the largest skin temperature difference of −4.9, −8.1, −6.7 and −7.6 °C, respectively. Besides, the relationships between thermal responses and between thermal responses and skin temperature were examined, as well as a thermal comfort assessment methodology was established for extremely low-temperature environments. • The heating characteristics of PCHs at about −20 °C have been analyzed. • An efficient convective PCHs was designed with a corrective power of 38.3K. • The face, hands, calves, and feet were the segments most prone to feel cold. • A thermal comfort assessment methodology was established and validated. [ABSTRACT FROM AUTHOR]

Thermal conditions with step changes and ramps in air temperature (T a) are universal in buildings. However, a comprehensive understanding of the influences of these dynamic thermal factors on thermal comfort remains elusive. This study investigated the physiological and psychological responses 16 healthy college students, including thermal sensation vote (TSV), thermal pleasure (TP), positive and negative affect schedule (PANAS), skin temperature, blood pressure, wrist pulse, and electroencephalography (EEG). The experimental procedure included step-changes from an office room (26 °C) to a meeting room under five different T a (22/24/26/28/30 °C) and subsequent ramping (down/up/cycles) back to 26 °C. After these different warm/cool thermal experiences, TSVs (−0.2 to 0.2) were insignificantly different and TPs (0.2–1.6) were significantly different (P = 0.006) at neutral condition of 26 °C. Specifically, TPs under neutral conditions were higher after a warmer thermal experience than after a cooler thermal experience. Under the same T a , TSVs were significantly lower (P = 0.031) by approximately 0.5, when T a ramping down compared to ramping up and stable warm conditions. The cheek temperature showed stronger correlations with TP and PANAS scores than with other body parts. The blood pressure was weakly correlated with TSV but exhibited a strong relationship with TP. Moreover, the TP and positive emotions exhibited strong negative correlations with wrist pulses and EEG at Theta (4–8 Hz). These findings offer insights into refining the prevailing thermal comfort models when considering dynamic thermal factors in shaping thermal perceptions. • TPs at neutral condition were significantly better after warm thermal experience in summer. • TSVs were 0.5 scale higher when T a ramp up than down (P = 0.031) in warm environments. • Cheek temperature has strongest correlations with TP and PANAS than other body parts. • The blood pressures have weak relationships with TSV but strong relationships with TP. • Positive emotions have strong correlations with wrist pulse and EEG at Theta (4–8 Hz). [ABSTRACT FROM AUTHOR]

Electroencephalograms have been proposed as potential physiological indicators to gauge the thermal comfort and cognitive performance of individuals in indoor environments, yet further experimental validation is required. In this study, a simulated experiment was conducted in a climatic room during summer, with temperatures set at 24 °C, 26 °C, 28 °C, 30 °C, and 32 °C. Twenty participants, attired in typical summer clothing (short sleeves and long pants totaling 0.39 clo), undertook cognitive tests assessing short-term memory and concentration while seated, alongside providing thermal comfort ratings. Electroencephalogram signals were continuously recorded from 14 electrode channels across the brain during the second cognitive test unit, spanning the 70th to 90th minute of experimental exposure. The relative power of electroencephalogram signals was computed and analyzed in conjunction with thermal comfort voting, revealing a significant impact of indoor temperature variations on α-band activity in the occipital lobe, with peak α-band relative power observed at 26 °C. Moreover, the whole-brain α-band relative power was significantly higher in states of thermal comfort compared to discomfort, particularly concentrated in the occipital lobe. Linear correlation analysis between cognitive test results and electroencephalogram signals indicated significant associations between the relative power of whole-brain β, δ, and θ bands and scores from the concentration-focused Flanker test. Channels O1 and P8 emerged as potential candidates for single-channel electroencephalogram signals, offering insights into thermal comfort status and cognitive performance related to concentration. [Display omitted] • Indoor air temperature significantly impacted occipital lobe α-band relative power. • The EEG α-band relative power was significantly higher during thermal comfort. • The relative power of β, δ, and θ bands correlated with cognitive performance. • O1 and P8 EEG channels can reflect thermal comfort state and cognitive performance. [ABSTRACT FROM AUTHOR]

This study investigated the correlations between the relative EEG power at different frequency bands under ceiling-fan-integrated air conditioning (CFIAC) systems. Twenty subjects participated in the experiments with the combinations of five air temperature levels (24, 25, 26, 27, and 28 °C) and six ceiling fan gears (Levels 1, 2, 3, 4, 5, and closed). The EEG signals and indoor environmental parameters (relative humidity, air velocity, and temperature) were recorded synchronously, and the thermal comfort online survey for each subject was obtained as well. The most comfortable combination was found when the air temperature was 27 °C and the fan speed was 0.3 m/s. When the air temperature was 25 °C, the relative EEG power in the different bands was least distinguishable, but when the temperature rose to 27 °C, it occurred an obvious change in different lobes. The δ, θ, β, and γ-bands significantly correlated with indoor setting temperature for the whole brain, but only the θ-band located at the occipital lobe significantly correlated with ceiling fan speed. The significance for the α-band with setting temperature and the β-band signal with air velocity varies with the subjects. Compared to the common air conditioning (CAC) system, CFIAC had a different effect on the relationship between relative EEG power and exposure environment. The airflow due to the ceiling fan may reverse this relationship between α-band, β-band, and IAT from positive (CFIAC system) to negative (CAC system). This study can contribute to developing wearable sensing data-driven thermal comfort evaluation models. • 25 °C was the most less distinguishable temperature for relative EEG power of different bands. • 27 °C was the up threshold cause the obvious change of the relative EEG power in different lobes. • Significance for α-band to air temperature and β-band to air velocity varies with subjects. • Just θ-band bands at the occipital lobe significantly correlated with ceiling fan speed. • Airflow reverse the relationship between α (β)-bands and indoor temperature. [ABSTRACT FROM AUTHOR]

• Acceptable definitions of thermal sensation for cold and hot water immersion provided are based on well-established thermoregulatory mechanisms. • A new thermal scale is advanced with respect to neurophysiology, psychometry, and linguistics. • Criticism against the potential use of common existing thermal sensation scales. • This scale will benefit healthcare professionals in prescribing aquatic exercise or managing lifesaving scenarios. Acceptable definitions of thermal sensation for cold and hot water immersion do not exist. The use of subjective thermal sensation scales remains unsolved with broad psycho-physiological, and semantic implications. We hypothesize that perception of thermal sensation could be a valid and reliable indicator for thermal strain during exposure in water. We aimed to provide a theoretical background for behavioral thermoregulation and neurocognition to support an integrated thermal sensation scale for estimation of thermal load during head-out water immersion. This research used a mixed methods approach. Domains were identified and items were measured for thermal load to examine the content validity. Thereafter, we formed an integrated scale based on standard 10,551 of International Organization for Standardization (ISO). Finally, we conducted a pilot study for the face validation of the scale based on a 30 min head-out water immersion at 26 °C in healthy adults (females, n = 4; males, n = 4; age: 22.6 ± 8.0 years; body mass, 67.7 ± 9.5 kg; height, 169.0 ± 5.6 cm). We identified three aspects (environment, physiological and behavioral thermoregulation) and a total of 18 items, of whom eight items (water temperature, immersion duration, core temperature, skin temperature, body heat storage, shivering, thermal sensation, and thermal comfort) were acceptable based on terms of scale-level content validity index (S-CVI = 92 %). Conditions incorporated into our scale included: icy < 12 °C, cold 12–24 °C, cool 24–29 °C, neutral 29–38 °C, warm 38–43 °C, and hot > 43 °C. We found excellent face validity based on a reported homogenous cool feeling and physiological thermoregulatory responses. Our study revealed our model could reasonably characterize body thermal load though whole-body thermal sensation based on well-established thermoregulatory mechanisms during water immersion. Further research is needed to validate the accuracy of our behavioral model in a variety of water temperatures and in a larger sample size. [ABSTRACT FROM AUTHOR]

Purpose - Occupants dwelling in hot climatic regions of India for a longer term are tolerable to high temperature levels than predicted by American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) standards. The purpose of this study is to evaluate the thermal sensations (TS) and neutral temperature of the occupants in naturally ventilated (NV) and air-conditioned (AC) classrooms of two technical institutions located in the same premises in the suburbs of Madurai. The main focus of this study is to understand the occupants' behaviour in response to the thermal conditions of the educational buildings particularly in the warm and humid climatic zone of Madurai. Design/methodology/approach - This research collected data through field studies. The data included 383 survey questionnaires from NV classrooms and 285 from AC classrooms, as well as on-site measurements of interior and exterior weather conditions. The TS results show that the students preferred well-designed NV classrooms than AC classrooms. A new adaptive comfort equation derived from this study can be applied to NV classrooms in warmand humid climates where mean outdoor temperature exceeds 40°C. Findings - The neutral temperature derived for NV classrooms in Madurai ranged from 29°C to 34°C. Thus, the occupants in the NV classrooms of the higher learning educational institutions in the warm and humid climatic region of Madurai can adapt well to higher indoor temperature levels than predicted by ASHRAE comfort levels with minimum adjustments. Research limitations/implications - The study was limited to only occupants in two premier higher learning technical educational institutions located in Madurai region within 5-10 km within the city limits to understand the implications of microclimate with respect to the urban context. Thus, further research is required to examine the tendency under local conditions in other regions beyond those applied to this study. Social implications - The findings of this study showed that occupants in higher learning educational intuitions in Madurai prefer NV classrooms than AC classrooms. Therefore, with rising demands of energy use for mechanical ventilation and the associated high cost for running AC buildings, architects should prioritize the design of energy efficient buildings through the optimal use of passive design strategies for ventilation and thermal comfort. This study gives a base data for architects to understand the adaptive limitations of occupants and design NV buildings that can promote natural ventilation and provide better thermal environments that can help increase the productivity of students. Originality/value - This paper was an attempt to develop the adaptive comfort model for NV classrooms in Madurai regions. There has been no attempt to identify the adaptive comfort levels of occupants in higher learning technical educational institutions located in warm and humid climatic region of India. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effect of prolonged steady state swimming with a wetsuit, on thermoregulatory and behavioural responses, in water of 25°C. Ten male swimmers participated in two 75-min swim trials, in one wearing a neoprene wetsuit (WS), and the other a conventional swimsuit (SS). The swimming intensity was controlled at 70% of swimmers' critical velocity (CV). Core (Tcore) and skin (Tsk) temperature, heart rate (HR), and behavioural modulators, were measured before, during and after swimming. A 2-way ANOVA for repeated measures with aFisher's 2SD test was used for multiple comparisons and a paired t-test with a Tukey post hoc analysis for pre and post measurements at p< 0.05. The results demonstrated an interaction of Tcore (p = 0.039), between time in the water and type of garment worn. Tcore with the WS initially increased until the 45th min and plateaued, while with the SS was continuously decreasing. HR was lower during swimming with the WS and higher with the SS. Thermal sensation and thermal comfort, were more favourable with the WS (p < 0.05). Thus, WS use during prolonged swimming, helped maintain Tcore levels, and improved thermal perceptions, at 25 °C. [ABSTRACT FROM AUTHOR]

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The quality of outdoor space is becoming increasingly important with the growing rate of urbanization. Visual, acoustic, and thermal balance degradation are all negative impacts associated with outdoor comfort in dense urban fabrics. Urban morphology thus needs assessment and optimization to ensure favorable outdoor thermal comfort (OTC). This study aims to evaluate the thermal performance of streets in residential zones of Liverpool, NSW, Australia, and tries to improve their comfort index (Physiological Equivalent Temperature) to reveal optimum urban configurations. This evaluation is done by investigating the following urban design factors affecting OTC using computational simulation techniques: street orientation, aspect ratio, building typology, and surface coverage. Our findings reveal that street canyon orientation is the most influential factor (46.42%), followed by aspect ratio (30.59%). Among the influential meteorological parameters (air temperature, wind speed, humidity and solar radiation), wind velocity had the most significant impact on the thermal comfort of the outdoor spaces in this coastal region, which typically experiences intense airflow. The results of our analysis can be utilized by multiple stakeholders, allowing them to understand and extract the most vital design factors which contextually influence the thermal comfort of outdoor spaces. Outdoor thermal comfort has a direct effect on the health and wellbeing of occupants of outdoor spaces. [ABSTRACT FROM AUTHOR]

In India, railways still continue to be the most prominent means of transport, especially non-air conditioned railway that carries around 3.5 billion people every year. Thermal comfort in these non-air-conditioned trains is predominantly influenced by windows and fans. The present study orients around the effect of fan air as well as naturally ventilated air on thermal comfort of passengers. The study is part of a field survey followed by an experimental investigation that was carried out in non-air-conditioned railway coaches during summer afternoon, with more than 1500 subjects of different gender and age category. The study significantly contributes in defining an elevated acceptable range of comfort air velocity inside a moving stock. The mean threshold air velocity where passengers responded a neutral PCV (passengers' comfort vote) is found to be 2 m/s which is much higher than conventional standards for enclosed static buildings and premises. The clear dominance of behavioral adaptation has been noticed in expression of thermal comfort by the passengers. This strengthens the idea of adopting some alternative method to deal with thermal discomfort of non–air-conditioned railway passengers. Here a novel term as 'zone of independence' (ZoI) has been defined at which the effect of air velocity becomes independent on passengers' comfort vote. This ZoI can significantly be utilized while optimization of thermal comfort in an ICF railway coach. • Thermal adaptation is more dominant in case of passengers as compared to building or office occupants. • Acceptable air velocity for thermal comfort at different relative humidity values varies within a range of 1.1 m/s to 2 m/s. • For higher humidity bands slightly lower air velocity preference has been recorded. • Need to redesigning of air velocity distribution for the existing Indian railway non-air-conditioned passenger coaches. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate the effect of draught on upper respiratory tract mucosal immunity, by assessing concentrations of lysozyme and secretory immunoglobulin A (S-IgA) in nasal lavage fluid. A total of 26 subjects were recruited and experienced 4 experiment conditions combined with two ambient temperatures (24 °C and 28 °C) and two air velocities towards the nape (0 m/s and 1 m/s). Physiological parameters, and subjective questionnaires (i.e., thermal sensation vote (TSV), thermal comfort vote (TCV), and air movement vote (AMV)) were also collected. Our findings revealed that physiological parameters fluctuated significantly under 24 °C, 1 m/s (p < 0.05). Significant decreases in lysozyme concentration occurred under both 24 °C, 1 m/s (p = 0.003) and 24 °C, 0 m/s (p = 0.017). S-IgA concentrations significantly decreased after one-day lag (p = 0.028) under 24 °C, 1 m/s. When TSV deviated from neutral, lysozyme concentrations decreased, especially when the TSV was [-3, −1.5) (p = 0.01). The S-IgA concentration increased when subjects felt slightly uncomfortable and decreased steadily for further discomfort. The proportion of subjects with decreased immune biomarker levels was minimized in the neutral TSV zone. The findings suggest that under the investigated scenarios, cold draught can suppress respiratory immunity by altering thermal sensations, with effects potentially persisting beyond exposure duration. Ensuring a neutral and comfortable thermal environment is pivotal for maintaining immunity stability. However, more experiments under a wider range of thermal parameters need to be performed to prove the robustness of current results. • Lysozyme level decreased when the result of thermal sensation votes deviated from neutral zone. • S-IgA level fluctuates when the result of thermal comfort votes deviated from comfortable zone. • The proportion of subjects whose immune level decreased was least with neutral thermal sensation. • The effect of cold draught on respiratory immunity may last for more than one day. • Respiratory immunity remains stable in neutral and comfortable thermo-environments. [ABSTRACT FROM AUTHOR]

This study clarifies the contact cooling effect of bare feet on human thermal physiology and sensation using a floor cooling system under hot environments. An experiment was conducted with 14 healthy young men and women using a water-cooled floor panel to investigate the cooling effects under Japanese summer conditions. The results revealed that the influences of the room temperature on the physiological parameters including blood flow, mean skin temperature, and sublingual temperature were more sensitive than that of the floor temperature. Nevertheless, the contact cooling of the soles with the floor temperature of 28 °C reduced the percentage of "very hot" and "hot" sensations of the entire body by 15.5 % when the room temperature was 30 °C. Moreover, the contact cooling of the soles at the room temperature of 30 °C increased heat flow from the soles while maintaining constant blood flow when the floor temperature was decreased. Thus, contact cooling of the soles was confirmed to be effective for heat mitigation in hot environments. However, the contact cooling was likely to cause thermal discomfort owing to the cold sensation as the room temperature decreased to 24 °C. Individual differences, in addition to the sex differences, occurred in the contact cooling effects on blood flow and skin temperature. Individual differences in blood flow were primarily caused by differences in basal metabolism and muscle mass. Further energy savings for space cooling and improved thermal comfort will be achieved by considering the individual differences for the floor cooling systems. • Influence of contact cooling on thermal physiology and sensation was investigated. • Individual difference of physiological response to floor temperature was observed. • Muscle mass affected the blood flow trends, mainly caused by gender differences. • Contact cooling reduced hot sensation by 15.5 % when the room temperature of 30 °C. • Contact cooling caused thermal discomfort due to cold at room temperature of 24 °C. [ABSTRACT FROM AUTHOR]

Thermo-physiological models allow the evaluation of the human response to thermal environments, assessing thermal comfort and (or) thermal stress due to exposure to heat and cold, in clothing and automotive research, and building simulation. Fifty years after the final version of the model developed by Stolwijk over the period 1966–1973, this paper describes a novel multi-cylindrical model which integrates the most recent advances in the active and the passive components and a thermal sensation model. The model, named THERMODE (THERMoregulation MOdel for Disuniform Environments) 2023, will be presented in-depth to allow its independent implementation by researchers in the field and favour further developments. Consisting of 14 blocks, 48 segments, and 193 nodes, THERMODE has been validated based on climatic chamber measurements carried out on nine groups of twelve subjects in a range of thermal sensations close to comfort (e.g., from slightly cool (−1) to slightly warm (+1) according to the ASHRAE scale). THERMODE predicts with acceptable accuracy core and local skin temperature values with deviations that do not exceed 0.5 °C in moderate environments. The thermal sensation model was validated on a sample of more than 4000 subjects and predicts with high accuracy the thermal sensation in the range from −1.2 to 2.0. THERMODE seems to be also reliable in a broader range of microclimatic conditions with skin and core temperatures close to those predicted by other models (e.g., JOS-3 or 3-D). • A thermo-physiological model for moderate and non-uniform environments is proposed. • Accurate clothing and sweating analysis and a thermal sensation module are included. • Predicted thermal sensation agrees with subjective investigation (4000 interviewed). • RMSE for mean skin and core temperatures is within 0.4 °C in moderate environments. • The model is reliable in severe environments and comparable with JOS-3 and 3-D models. [ABSTRACT FROM AUTHOR]

Mean skin temperature (MST) is one of the most important physiological metrics in sleep-environment research. Commonly used MST formulas are mainly derived from heat transfer calculations at non-sleeping postures, but not theoretically suitable for the purposes of sleep researches. A winter sleep experiment was carried out in three stable thermal environments (16 °C/20 °C/24 °C), and its data were used to establish two kinds of MST formulas. Based on the heat transfer process of different body parts at supine posture, a new calculating formula for mean skin temperature of covered body (CMST) which applicable to sleeping heat transfer evaluation was presented; comparing the heat transfer value calculated by the new formula with traditional formula, it can be found that the differences significantly increased as the ambient temperature decreased (p < 0.001). Based on the calculated thermal sensitivities and area proportions of 10 body parts, a new MST formula suitable for assessing sleeping thermal sensation was established; the new TSV-MST formula exhibited a larger regression coefficient (0.75) in comparison to the traditional formula (0.67), which means that the MST calculated with new formula can be more predictive of sleeping thermal sensation. In overall, the newly proposed CMST and MST formulas are able to theoretically explain and satisfy the application needs of current sleep researches, and this study supports the viewpoint that different MST formulas should be adopted for different research purposes. • Commonly used MST formulas are not theoretically suitable for the purposes of sleep researches. • A new CMST formula suitable for sleeping heat transfer calculation was established. • A new MST formula suitable for sleeping thermal sensation evaluation was established. [ABSTRACT FROM AUTHOR]

The thermal comfort of elderly people in warm indoor environments is important because of their higher risk of heat stress. The use of local cooling devices may help alleviate heat stress. In this study, 26 elderly participants were recruited for climate chamber experiments in neutral (26 °C, 40 % relative humidity (RH)), slightly warm (29 °C, 40 % RH; 28 °C, 60 % RH), and warm (33 °C, 40 % RH; 32 °C, 50 % RH) environments. Three local cooling devices were tested: a table fan, evaporative cooling device, and air-cooled jacket. This study found, in different warm environments, the use of local cooling devices by the elderly results in an mean skin temperature decrease of no more than 0.5 °C. The thermal sensation in the head and torso has the most significant impact on overall thermal sensation. The mean skin temperature (MST) remains an effective physiological indicator for estimating overall thermal sensation after using local cooling devices. The skin temperature in the head, limbs, and extremities plays a substantial role in predicting overall thermal sensation. The thermosensory mean skin temperature (TMST) proposed based on the skin temperature of these parts can more accurately predict overall thermal sensation than MST. This study provides a reference for the development of future local cooling devices. This study has implications for guiding the selection of devices for nursing homes or residential environments for the elderly, and it can be utilized to formulate recommendations for improving device design. • The reduction in mean skin temperature of no more than 0.5 °C after using local cooling devices in diverse conditions. • Significant declines in local thermal sensation are observed in both exposed and unexposed body parts. • The thermal sensation in the head and torso exerts about 70% influence on overall thermal perception. • Skin temperature in the head, limbs, and extremities has the strongest correlation with thermal sensation. • The thermosensory mean skin temperature which considered the influence of local thermal sensation have a better correlation. [ABSTRACT FROM AUTHOR]

The use of cooling techniques in a tropical climate can limit the increase in core body temperature and therefore improve physical exercise performance. However, little is known about the impact of cooling on psychological functioning. The aim of this study was to determine whether cold water intake influences environmental perceptions, affects, and attention depending on the climate condition (tropical climate vs. neutral climate). The study followed a mixed 2 × 3 crossover design (climate as the within factor, tropical climate vs. neutral climate; water intake as the between factor, cold water vs. neutral water vs. no water). Participants reported lower thermal comfort, had positive affect scores, had lower attention performance scores, and had higher thermal sensation and negative affect in tropical climate compared with neutral climate. It was shown that drinking water at room temperature in a neutral climate causes the best thermal comfort scores, and drinking water at room temperature in tropical climate causes the worst scores. Cold water intake, which had no notable influence on positive affect scores in a tropical climate, had a deleterious effect in a neutral climate. Drinking cold water as a technique to limit the deleterious effects of tropical climate on environmental perceptions, affect, and attention is discussed. [ABSTRACT FROM AUTHOR]

Thermal comfort is an important component of any work setting and can be difficult to achieve in the complex OR environment. This comparative descriptive study sought to identify factors affecting the thermal comfort of perioperative personnel in the OR (N = 68). Researchers used the American Society of Heating, Refrigerating and Air‐Conditioning Engineers Thermal Sensation Scale and researcher‐developed surveys to collect data. The mean reported thermal comfort level was −0.44 (standard deviation 1.3), which is within acceptable parameters. Factors affecting thermal comfort were gender, professional role, and wearing additional clothing. Additionally, participants who complained about temperature or ventilation were less likely to report thermal comfort levels in the normal range. Health care facility leaders should consider the comfort needs of perioperative personnel when making purchasing decisions about ventilation systems and surgical clothing; however, they also should consider other factors (eg, surgeon comfort, permeability of protective clothing to blood and other body fluids). [ABSTRACT FROM AUTHOR]

Background: This study examined the effects of immersion in stirred, high-concentration, artificial carbonic acid water on body cooling. Methods: Seven healthy male students (23 ± 2 years old) participated in the experiment. Signed informed consent was obtained from all subjects before the experiment. The subjects changed into shorts and T-shirts and entered an experimental room (with room temperature controlled at 30 °C and relative humidity maintained at 70%) at least 30 min before starting the experiment. After starting the experiment, the subjects were asked to rest on an exercise bike for 5 min and then pedal for 20 min. The exercise load was set to reach 50% of each subject's presumed maximum oxygen intake at 5 min after starting exercise. Subjects then continued pedaling for 1 min to cool down. After this exercise, subjects sat on a chair and immersed forearms in tap water or artificial carbonic acid water (CO2 water) at 25 °C for 20 min. During immersion, tap water or CO2 water was stirred slowly with a pump. After immersion, subjects rested for 10 min. Skin temperature and skin blood flow (left forearm), as well as heart rate and ear canal temperature, were measured continuously. Thermal sensation and thermal comfort were measured intermittently. Results: Skin blood flow of the immersed forearms was higher in CO2 water than in tap water during immersion. The blood flow in the last 5 min (average at rest was 100%) was significantly higher in CO2 water (290.85 ± 84.81%) than in tap water (104.80 ± 21.99%). Thermal sensation and thermal comfort were not different between conditions. Ear canal temperature significantly declined more in CO2 water (− 0.56 ± 0.31 °C) than in tap water (− 0.48 ± 0.30 °C) during immersion. Conclusions: Our study suggests that immersion of the forearms in slowly stirred CO2 water at 25 °C reduces core temperature elevated by heat stress or exercise more effectively than does tap water at the same temperature. Immersion of the forearms in stirred CO2 water at 25 °C could be useful as a preventive measure against heat stroke from summer work or exercise. [ABSTRACT FROM AUTHOR]

India is a vast country spread across five climatic zones. The current Indian building codes specify thermal comfort standards for naturally ventilated offices only. This paper presents a year-long field study carried out during 2015–16 to investigate thermal comfort in naturally ventilated (NV) classrooms of three government residential schools located in the composite climatic zone of India. A total of 1890 data sets were collected from children and teenagers in the age group of 10–18 years. The students in naturally ventilated classrooms were found to be more adaptive than what is prescribed in the ASHRAE thermal comfort standards. Indoor operative temperatures of 28.2°C and 19.4°C were recorded as the neutral temperatures of the summer and winter seasons, respectively. The study proposes a thermal comfort range of 16°C to 33.7°C for 80% acceptability. The study also proposes an adaptive thermal comfort model for naturally ventilated secondary school classrooms in composite climatic zones. The results show that students are adapted to higher temperatures in classroom environments. The study provides a baseline for further research in developing thermal comfort standards for secondary school classrooms in India. [ABSTRACT FROM AUTHOR]

A comfortable building environment plays a vital role in enhancing both the physical and mental well-being of its occupants. In recent years, the assessment of building thermal environments has gained significant attention. The assessment methodology is shifting from subjective evaluations to more physiological assessments. However, the exploration of facial muscles in this context has remained largely uncharted territory. The primary objective of this research was to investigate the characteristics of facial electromyography (fEMG) in a cold environment and examine its potential for assessing thermal comfort. The experiment was divided into two parts. The first part focused on understanding fEMG characteristics in the time domain, frequency domain, and phase during activities like speaking, expressing emotions, and exposure to cold conditions. The second part aimed to study the recovery process of fEMG after cold exposure, achieved by increasing clothing insulation and raising air temperature. The findings revealed significant distinctions in fEMG characteristics when subjects engaged in speaking (notably in the low-frequency component of the anguli oris muscle), expressing emotions (with a prominent low-frequency component in the zygomatic muscle), or experiencing cold conditions (highlighted by the high-frequency component of the masseter muscle). Interestingly, augmenting clothing insulation in the body region posed challenges in improving facial muscle electrical activity, while raising air temperature effectively alleviated facial muscle tension. This study represents the pioneering application of fEMG in indoor thermal comfort evaluation. It offers a physiological foundation for assessing thermal comfort based on facial skin temperature and facial expressions. Furthermore, the research contributes valuable data that can support the advancement of wearable devices and smart building systems. • Using facial electromyography to evaluate thermal comfort is a new attempt. • The characteristics of different facial activities in time domain, frequency domain and phase are obvious. • Facial muscles are very sensitive to temperature, especially masseter muscles. • Increasing clothing insulation is difficult to alleviate facial muscle discomfort caused by cold exposure. • Facial electromyography has great potential in the application of wearable devices and smart buildings. [ABSTRACT FROM AUTHOR]

The thermal comfort and thermal sensation of occupants can significantly impact the overall performance of the building. However, very little is known about how occupants perceive or thermally respond to their building interior layouts or what factors affect their thermal comfort and sensation, particularly in low-income residential homes. Through a post-occupancy evaluation of 394 occupants from 190 households in Chittagong, Bangladesh, this study examines the socio-demographic factors (i.e., gender, age, and home ownership) that influence occupants' thermal comfort and sensation. The chi-square, Cramer's V, and Lambda tests were used to statistically analyze the impact of selected socio-demographic factors. The results showed that female occupants were significantly less satisfied than male occupants with their existing thermal environment. However, the study did not find any influence of age or home ownership on occupant thermal comfort. Furthermore, comprehensive agent-based modeling (ABM) was implemented to support the results of the statistical analysis of the influence of gender on occupants' thermal comfort levels. The ABM was designed based on the theory of planned behavior. As a simulation output, the ABM model stochastically estimated occupants' thermal comfort and sensation level in terms of the predicted mean vote. Similar to the statistical analyses, the results of the ABM also indicated better thermal comfort and thermal sensation for male occupants than for female occupants. The results of the study can serve as a guideline for better understanding the socio-demographic factors involved in the modeling or remodeling of occupant thermal comfort in developing economies. • Occupants' thermal comfort/sensation is studied based on socio-demographic factors. • A questionnaire survey is conducted for 394 occupants from the low-income context. • An integrated approach is adopted using statistical analysis and ABM-SD-BIM. • Gender indicates a significant socio-demographic factor using both methods. • This study reveals the influence of socio-demographic factors on thermal comfort. [ABSTRACT FROM AUTHOR]

A non-uniform thermal environment significantly affects human physiological responses and even harms health. Specifically, a non-uniform bathing thermal environment is particularly deadly for older adults. Although each body part's arterial blood flow changes in the bathing thermal environment, little research has been conducted on the physiological responses of participants of different ages. Herein, we conducted a series of bathing experiments on three healthy participants aged 25, 52, and 71. The aim of these experiments to elucidate and analyze the thermal sensations and physiological responses of the participants in a non-uniform bathing thermal environment (i.e., the upper body was exposed to air, whereas the lower body was immersed in hot bathwater). We found that the non-uniform thermal environment greatly influenced a variety of physiological parameters and increased the participants' heart rates and blood flow. The youngest participant (i.e., the 25-year-old) and oldest participant (i.e., the 71-year-old) had the fastest and slowest perception of thermal sensation, respectively. The physiological responses changed significantly with the perception of thermal sensation change for the three participants. Unlike the other two participants, the oldest participant had decreased blood pressure and slowly increased thermal sensation. In addition, the oldest participant in a short bathing time had minor thermal health risks than younger participants due to exhibiting the slowest thermal response. However, older adults may experience greater thermal health risks due to their relatively slow thermal response in long-time and high-temperature bathing environments. • Three aged participants' blood flow was measured in bathing thermal environment. • Youngest participant showed the greatest blood flow and thermal sensation changes. • The oldest participant had the lowest thermal risk during short time bathing. • Older adults may reduce thermal risk due to slower thermal responses. [ABSTRACT FROM AUTHOR]

Abstract Thermo-physiological modelling has become a frequently used and valuable tool for simulations of thermoregulatory responses in a variety of applications, such as building and vehicular comfort studies. To achieve reliable results, it is necessary to provide precise inputs, such as clothing thermal parameters. These values are usually presented in a standing body position and scarcely reported locally for individual body parts. Moreover, as an air gap distribution is both highly affected by a given body position and critical for clothing insulation, this needs to be taken into account. Therefore, the aim of this study was to examine eight probable approaches to assess the clothing parameters using state-of-the-art measurements, analytical and empirical models, and estimation. Next, we studied the effects of the eight clothing inputs on predicted thermo-physiological response under the same environmental conditions conducted with the Fiala model. Secondly, the study focuses on differences between seated and standing positions, both using two clothing sets representing typical European, indoor, summer and winter ensembles. The results show clear differences in clothing thermal properties between sitting and standing positions on both lower limbs and torso. The outputs of the eight examined methods showed discrepancies between them, in the range of up to 200%. The discrepancies from the eight clothing inputs were also propagated in the results of thermo-physiological responses. These varied significantly in terms of their impact on predicted thermal sensation, highlighting the importance of using adequate inputs for modelling. Highlights • Typical methods for local clothing properties revealed up to two-fold discrepancies. • When seated thermal and evaporative resistance of clothing drops compared to standing. • The discrepancies influenced skin temperature by up to 1.3 °C globally and 2 °C locally. • Thermal sensation and wet discomfort were consequently substantially dispersed. [ABSTRACT FROM AUTHOR]

Abstract The aim of this study was to find the most favourable shape of the front panel perforation shape, which would allow us to obtain the greatest cooling effect and – at the same time – be positively perceived by the people. The capacity of the personalized ventilation (PV) system to affect human thermal sensation, with different shapes of front panel perforation used, was analyzed. Once the pilot study was conducted, it used a rectangular nozzle of front pattern size 320 mm × 125 mm and six different front patterns perforation shapes with round holes were tested. Operational parameters such as: airflow 20 l/s, supply air temperature at 24 °C or ambient temperature at 28 °C were invariable. The experiment consisted of a two-stage analysis of air jets characteristics and of tests in which people participated. Twenty-five male volunteers, at the age of 22–23 were engaged. They their assessed thermal sensation and completed relevant questionnaires. On the basis of the results of the above study, differences in jet characteristics depending on the pattern shapes and their different impact on thermal sensation of the volunteers were demonstrated. The biggest cooling effect was obtained using front panels with small hole size (d = 5 mm). These perforations allowed us to obtain a more even air outflow from the entire panel. This ensured a broader airflow of lower velocity, reaching and affecting a larger area. With holes of larger size (d = 15 mm), air outflow occurred mainly through the central part, which produced narrow jets of higher velocity. Highlights • Determining velocity profiles for personalized jets with different front pattern shapes. • Questionnaire based assessment of the impact of different front patterns on thermal sensation of the occupants in PV. • Demonstrating statistically significant differences between the front patterns used and thermal sensation of the volunteers. [ABSTRACT FROM AUTHOR]

Objectives: To investigate whether the exercise performance benefits with neck cooling in the heat are attributable to neck-specific cooling, general body cooling, a cooler site-specific thermal perception or a combination of the above.Design: Counter-balanced crossover design.Methods: Twelve healthy participants cycled in the heat (34°C, 30% relative humidity), at a power output (PO) self-selected to maintain a fixed rating of perceived exertion (RPE) of 16. Each participant underwent four experimental trials: no cooling (CON), neck cooling (NEC), abdominal cooling (ABD), or neck cooling with menthol (MEN). Participants cycled for 90min or until their workload reduced by <70% of their initial PO. Changes in PO, rectal temperature (Tre), mean skin temperature (Tsk), whole-body thermal sensation (TSwb) and thermal sensation of the neck (TSneck) were recorded throughout.Results: The mean reduction in PO throughout exercise was similar (p=0.431) for CON (175±10W), NEC (176 ±12W), ABD (172±13W) and MEN (174±12W). The ΔTre at the end of exercise was similar (p=0.874) for CON (0.83±0.5°C), NEC (0.85±0.5°C), ABD (0.82±0.5°C) and MEN (0.81±0.5°C). TSwb was cooler (p<0.013) in MEN (125±8mm) compared to CON (146±19mm), NEC (135±11mm) and ABD (141±16mm).Conclusions: No differences in exercise performance or thermal strain were observed in any of the cooling trials compared to the CON trial, despite significantly cooler TSwb values in the MEN and NEC trials compared to the CON trial. These findings differ from previous observations and highlight that the benefit of neck cooling may be situation dependent. [ABSTRACT FROM AUTHOR]

Although outdoor thermal comfort has gained increasing research attention, meteorological conditions and thermal sensation in different urban settings in high-density cities have not been systematically studied from the perspective of urban planning and design. Considering the potential relationship between environmental quality and thermal sensation in outdoor spaces— an emerging topic in perceived comfort, this study offers a new approach for planning and design for climate resilience in cities. This paper presents the results of an outdoor thermal comfort survey conducted on hot summer days in Hong Kong. Diverse patterns of PET-comfort ratings relationships were found in different urban settings. The study revealed that air temperature, subjective assessments of solar radiation and wind environment were strong determinants of thermal sensation and evaluation. In our analysis, wind condition showed a significant indirect effect on comfort through subjective perception. Statistical modelling showed that subjective perceptions on microclimate condition and comfort are moderated by various aspects of environmental quality. The findings of this study help inform future design for climate resilience in outdoor urban spaces in hot-humid subtropical cities. [ABSTRACT FROM AUTHOR]

Abstract Older people are very likely to experience transitions among spaces with different temperatures in daily life. But little has been known about their thermal comfort and physiological responses to these temperature steps. This study investigated 18 healthy older people's thermal perceptions and physiological parameters under cold and warm exposures with 3/5/6 °C temperature steps. The results showed that subjects' thermal sensation was sensitive to all moderate temperature steps, but their thermal comfort perception could only distinguish temperature changes greater than 5 °C. Thermal unacceptability was only observed when subjects' tympanic temperature reached at 37.08 °C. Also, we found older people need more than 50 min time to get their mean skin temperature steady after cold stimuli, while they only need <24 min after warm ones. Cold stimuli could significantly boost subjects' blood pressure, respiratory rate, blood oxygen saturation, and depress heart rate. To predict older people's transient thermal sensation after temperature steps, we proposed two regression models for cold and warm exposures respectively. Based on the above observations, we suggest older people should try their best to avoid large step temperature changes, especially for cold side steps. Highlights • The effects of four temperature steps on older people's thermal perceptions and physiological parameters were tested. • Overshooting phenomenon on thermal sensation was not observed in this study. • Two regression models were proposed to predict older people's cold or warm thermal sensation after a temperature step. • A cold temperature step can markedly affect older people's cardiovascular system and respiratory system. [ABSTRACT FROM AUTHOR]

Abstract The IAQ and thermal comfort in residential kitchen are two major concerns in built environment. The ventilation effectiveness is closely related to the IAQ of the residential kitchen. Therefore, it is necessary to design a cost-effective kitchen ventilation system. In this study, a field experimental study was conducted on a push-pull kitchen ventilation system. The experiment was divided into two parts. The first part was to test the capture efficiency of the push-pull ventilation system under various working conditions. The second part was to investigate the thermal comfort of the human body during cooking process with and without air curtain in winter. The results show that the push-pull ventilation system can effectively improve the capture efficiency of the range hood, and the low-momentum make-up air and the reasonable air distribution around the stove are important to obtain good performance. The optimal working condition of the push-pull ventilation system is a range hood mid gear plus an air curtain velocity of 0.5 m/s when the kitchen window is closed. In winter, when people enter the non-air-conditioned kitchen from the air-conditioned room, the thermal sensation and thermal comfort of people were all decreased significantly. However, they can be improved during cooking processes. The prediction results show that models which used skin temperature as input parameter can predict the thermal sensation of most parts of human body in kitchen. However, the prediction correction model is still needed for the body parts with movement or exposure to severe heat radiation. Highlights • Air curtain with optimal velocity can improve capture efficiency of range hood. • In winter, cooking process can improve thermal comfort of human body. • Air curtain has no significant effect on thermal comfort of human body in winter. • Different thermal sensation models were compared for kitchen environment. [ABSTRACT FROM AUTHOR]

Abstract Research on outdoor comfort generally focuses on the thermal sensation as a substitute for actual comfort. The assessment of outdoor comfort, however, is complex in nature because it involves various contextual settings in open spaces, individuals' social demographics, and psychological factors. In contributing to the existing literature, this study attempts to extend the modelling framework of outdoor comfort assessment by incorporating physical microclimate, spatial contexts, social demographics and individuals' subjective perceptions, expectations and preferences. A path analysis is conducted to capture the direct and indirect effects of various factors on comfort using the data collected in a field experiment. Results show that the causal dependency, which is normally simplified in existing studies, can be better illustrated with the indirect effects through mediators. The use of objective indicators and individuals' subjective factors are fundamental to adequately capture the actual comfort in urban public spaces. Highlights • Extended the modelling framework for outdoor comfort assessment. • Incorporated individuals' perception, expectation and preference. • Investigated the endogenous and exogenous relationship with actual comfort. • Captured indirect effects through mediators. [ABSTRACT FROM AUTHOR]

Abstract Most thermal comfort standards and guidelines currently in use do not consider occupants' adaptive capabilities associated with real-world situations when predicting occupant thermal comfort in mechanically conditioned buildings, although the adaptive approach is commonly applied to naturally ventilated buildings. These standards are generally based on results derived from experiments conducted in climate-controlled chambers. In some cases, this can lead to overcooling of buildings while still not satisfying most of occupants. One common method to reduce peak electricity demand is via temporarily increasing cooling temperature setpoint during peak hours. However, the potential negative impacts on occupant thermal comfort and wellbeing calls for further study on this. This paper describes a study conducted on a university campus in the United States that investigated occupants' thermal sensation, acceptability, and preferences corresponding to increased cooling temperature setpoint in parts of the building that are temporarily occupied. The results revealed a potential for at least temporarily increasing cooling temperature setpoint (at least 2 °C) across this campus without impairing occupant thermal comfort. For operative temperatures between 22 and 24.5 °C, the average Actual Mean Vote (AMV) for the class sections remained in the ASHRAE comfort range and the self-reported thermal acceptability was above 80%. Occupants' thermal acceptability dropped to less than 80% when the temperature was increased to more than 24.5 °C, and the AMV values increased to more than 0.5 (on ASHRAE 7-point scale). The percentage of occupants who were involved in some sort of adaptive behavior did not considerably change with room temperature. Highlights • By temporarily increasing indoor operative temperature in campus classrooms from 21 to 25 °C, thermal acceptability remains above 80%. • At 23.5 °C, occupants' mean thermal preference and their actual mean votes equals zero, while thermal acceptability is above 90%. • Occupants' adaptive behavior in this study, with limited adaptive options, is not a function of the operative temperature. • Heat balance model under-predicts the percentage of dissatisfied occupants at environmental conditions warmer than neutral. [ABSTRACT FROM AUTHOR]

BACKGROUND: Precooling (PC) before exercise may help prevent severe hyperthermia and exertional heatstroke (EHS). Before clinicians can advocate PC as an EHS prevention strategy, it must effectively mitigate factors associated with EHS development while not lessening the effectiveness of EHS treatment. Therefore, this study determined if PC affected rectal temperature (Trec), body heat storage, heart rate (HR), ratings of perceived exertion (RPE), thermal sensation, sweat rate, and postexercise cold-water immersion (CWI) Trec cooling rates. METHODS: In this randomized, crossover, counterbalanced study, 12 subjects (6 men, 6 women; age = 22 ± 2 yr; mass = 73.5 ± 7.9 kg; height =171 ± 7 cm) underwent 15 min of CWI (10.0 ± 0.03°C) in an environmental chamber (38.6 ± 0.6°C; 36 ± 2% humidity). After a 10-min rest, they exercised to a Trec of 39.5°C. Subsequently, they underwent CWI (9.99 ± 0.03°C) until Trec reached 38°C. On control (CON) days, the same procedures occurred without the 15-min PC intervention. Trec, HR, thermal sensation, and RPE were measured at various times before, during, and after exercise. RESULTS: PC lowered body heat storage and Trec by 15.7 ± 15.0 W ⋅ m-2 and 0.42 ± 0.40°C, respectively, before exercise. Subjects exercised significantly longer (PC = 66.7 ± 16.3 min, CON = 45.7 ± 9.5 min) and at lower Trec (~0.5 ± 0.5°C) and HR (~10 ± 7 bpm) following PC. PC significantly lowered sweat rate (PC = 1.02 ± 0.31 L ⋅ h-1 CON = 1.22 ± 0.39 L ⋅ h-1), but did not affect RPE or CWI cooling rates (PC = 0.18 ± 0.14°C ⋅ min-1; CON = 0.19 ± 0.05°C ⋅ min-1). Thermal sensation significantly differed between conditions only at pre-exercise (PC = 3 ± 1, CON = 5 ± 0.5). DISCUSSION: PC delayed severe hyperthermia and mitigated dehydration without affecting thermal perception or cooling rates posthyperthermia. PC may help prevent dangerous hyperthermia in athletes. [ABSTRACT FROM AUTHOR]

Highlights • Different thermal comfort indices were compared based on the fundamentals. • Field surveys were carried out for validation of the thermal comfort indices. • The relationships between the indices and MTSV were undetermined for hot outdoor environments. • The ranges of heat stress category and PMV need to be modified for hot outdoor environments. Abstract Comfortable and healthy outdoor microclimates are beneficial to sustainable urban development. Based on a comprehensive comparison of some currently frequently used thermal comfort indices, including PMV, WBGT, PET, SET*, and UTCI, the differences among these indices are significant in dealing with the fundamental energy balance model, descriptive equations, and application boundary conditions. In order to validate these indices, a subjective questionnaire survey with field measurements was carried out on a university campus in Guangzhou in southern China. Results revealed strong linear relationships between operative temperature and mean radiant temperature (T mrt), WBGT, PET, SET*, UTCI, as well as PMV. However, the relationships between these thermal comfort indices and the mean thermal sensation vote (MTSV) are not clear for a hot outdoor environment, especially when the operative temperature was above 34 °C. The ranges of the heat stress category and PMV need to be modified for the evaluation of hot outdoor environments. [ABSTRACT FROM AUTHOR]

The purpose of the paper was to assess pedestrians' thermal perception, in the semi-arid climate of Constantine, Algeria, with particular emphasis on the protocols implemented in public spaces during the post-COVID-19. Three outdoor public spaces were selected in August 2021 to conduct a field study involving 254 respondents, randomly assigned. The adopted approach combined objective and subjective assessment, as well as numerical simulations using ENVI-met. Accordingly, microclimate monitoring and a questionnaire survey were carried out simultaneously from 7 a.m. to 7 p.m. in each study site. A strong association was found between the combined microclimate parameters (objective variables) and thermal sensation of the surveyors with (R2 = 0.74). Besides, Kruskal-Wallis H test revealed that the subjective thermal sensation was significantly influenced (p-value <0.05) by thermal history and purpose of visit (subjective variables). Most interviewees preferred 'move to shade' measure as a remedial behavior to reduce their thermal discomfort. Further, a neutral temperature of 22.7 °C PET was obtained by a linear regression between the Mean Thermal Sensation Votes (MTSV) and Physiological Equivalent Temperature (PET), the comfort range was estimated between 18.6 °C ≤ PET≤ 26.8 °C during summer. Regarding the COVID-19 pandemic effects, the Chi-square test suggests that the frequency of pedestrian visits was statistically independent of the imposed pandemic measures. However, the planned activities were affected by social distancing and the use of face masks increases pedestrians' thermal discomfort. Overall, the study highlights the significance of environmental and non-environmental factors to improve outdoor thermal comfort, and ensure human well-being. • Triangulation of field measurements, surveys, and simulations is essential for assessing outdoor thermal perception. • Thermal adaptation and behavioral adjustments are vital for enhancing the evaluation of human thermal comfort. • Neutral PET and comfort range during summertime in Constantine were determined. • Calibration of the thermo-physiological indices in semi-arid climates is required. • The COVID-19-enforced measures influenced pedestrians' outdoor behavior during the post-pandemic. [ABSTRACT FROM AUTHOR]

Perceived control is a psychological state experienced by individuals in their environment and is considered a critical factor in adaptive thermal comfort models. A longitudinal study lasting two and a half years was conducted in Xiamen, China, to investigate the impact of perceived control on outdoor thermal comfort. The study, carried out in an outdoor living laboratory with 56 participants, explored conditions with and without perceived control. Subjective thermal perception and thermal environment parameters were collected. Differences in outdoor thermal comfort across summer, transition seasons, and winter between participants with and without perceived control were established, and conversion formulas for thermal sensation votes were obtained. The study results indicate that: (1) The neutral mPET of participants with perceived control were 26.4 °C, 24.9 °C, and 22.3 °C in summer, transition seasons, and winter respectively, while those without perceived control were 25.2 °C, 24.6 °C, and 22.8 °C respectively. (2) Participants without perceived control tend to prefer different thermal environment (either cooler or warmer). (3) Perceived control expanded the range of acceptable thermal environment for participants in all seasons. (4) Perceived control can reduce outdoor thermal sensitivity and make participants more likely to achieve a comfortable thermal experience, but the effect varies under different thermal conditions. (5) Regardless of perceived control, global radiation and air temperature are the most crucial environmental factors affecting thermal sensation, while the impact of clothing thermal resistance and duration of stay on thermal sensation is enhanced under conditions without perceived control. • Employed a living lab for long-term study on autonomous activity thermal comfort. • Compared outdoor thermal comfort of participants with and without perceived control. • Participants with perceived control more easily found comfort in outdoor heat. • Provided TSV conversion formulas for conditions with and without perceived control. [ABSTRACT FROM AUTHOR]

Creating an optimal indoor thermal environment that meets the needs of diverse populations is a crucial aspect of building design. Given the escalating frequency of population migration and the widespread adoption of centralized heating systems, it is important to establish the effects of various prior thermal histories on human adaptability to centralized heating environments. In this study, 15 subjects with no prior experience of heating in hot summer and cold winter regions (HSCW) and 13 subjects with prior experience of heating in cold regions (C) were selected for a 40-day follow-up study at a university in Qingdao. In total, 992 valid responses were obtained from the questionnaires. The results indicated that prior thermal history had a notable influence on thermal perception in centrally heated environments, with those lacking heating experience reflecting a better initial perception of heat. Specifically, in a classroom environment, the differences between the two groups, in terms of thermal sensation, thermal acceptability (percentage of acceptance), and thermal expectation (percentage of desiring "warmer") decreased from 0.26, 12%, and 19% in the first cycle to 0.03, 2%, and 3% in the fourth cycle (25–32 days), respectively. The difference in thermal comfort also reduced from 0.23 in the second cycle (9–16 days) to 0.04. Similar trends were observed in the dormitory environment, indicating that the duration of the impact of heat experience on adaptation to the centrally heated environment was 32 days. The results of this study are useful for describing the dynamic thermal acclimatization of different populations in unfamiliar thermal environments and for providing indoor thermal environments that match the thermal preferences of residents with different thermal experiences. • Thermal history has a significant impact on the thermal perception of the central heating environment. • The duration of the impact of thermal history on the adaptation to indoor central heating environments is 32 days. • Adaptive behavior, such as clothing adjustment, reflected differences and convergence in thermal perceptions. [ABSTRACT FROM AUTHOR]

Thermal comfort is a crucial aspect of building design that can have a direct impact on people's health, productivity, and overall comfort. Evaluating indoor thermal comfort could be done through various methods, and this paper explored the feasibility of using electroencephalogram (EEG) critical dynamic parameters to evaluate thermal comfort. The study aimed to determine the critical dynamic characteristics of brain activity under different thermal conditions, and to establish the relationship between comfort and brain energy consumption. The experiment involved three conditions of cold, neutral, and hot environment, with 20 participants' EEG, thermal sensation vote (TSV), and thermal comfort vote (TCV) collected. The study calculated the critical dynamic parameters of EEG, including the mean frequency, avalanche size, avalanche duration, and branch parameters of brain activity at different temperature levels. The results showed that the parietal occipital lobe, right frontal lobe, and temporal lobe were sensitive to cold and hot, with brain activity tending to be large-scale and long-term during cold environment. In addition, 80% and 35% of the participants had higher brain activity energy consumption in cold environment and hot environment, respectively, compared to the neutral environment. This study represents a new interdisciplinary approach combining medicine and engineering to evaluate indoor thermal comfort, and provides a new research framework and knowledge system for understanding the cognitive activities of the brain in indoor thermal environments, as well as the application of smart buildings. • The critical dynamic features of brain activity were analyzed under thermal comfort. • Attempt to demonstrate that the brain consumes less energy during comfort state. • This research provided a new method for assessing thermal comfort. • A research framework based on EEG dynamic parameters was proposed. • The regions of the brain that are sensitive to cold and heat were identified. [ABSTRACT FROM AUTHOR]

Understanding thermal comfort in dynamic environments is vital for developing various air temperature control strategies that consider energy flexibility. However, studies on the quantitative effects of air-temperature change rates and directions on human thermal responses in thermal environments with temperature ramps (TRs) are limited. In this study, 22 sex-balanced young adults were recruited to investigate the thermal perceptions and physiological responses to room air TRs at rates of 0.10–0.30 °C/min in a climate chamber. The results revealed that the air temperature change direction had no effect on the mean skin temperature (T skin) but significantly affected the thermal sensation vote (TSV), that is, the TSV was approximately 0.5 scales lower when the temperature was decreasing than when it was increasing (P < 0.05). Moreover, the slow change rates of T skin within the range of ±0.07 °C/min had no significant effect on dynamic TSV, unlike that in step-change environments with higher change rates. The head was the most thermally sensitive body part with the highest TSV/ T skin values and change rates of T skin (up to ±0.08 °C/min) in warm TR environments. In most cases, the thermal response of limbs was delayed. The thermal experience and adaptation levels of occupants may play essential roles in thermal perceptions within TR environments. Preliminary thermal comfort models suitable for hot summer climates were proposed in this study, which could be used in TR control strategies, such as intermittent cooling or demand response control. • Effect of different TRs on thermal responses was studied in warm environments. • TSV was about 0.5 scale lower when temperature dropping than rising (P < 0.05). • Slow change rates of T skin within ±0.07 °C/min have no significant effect on TSV. • TSV and TCV prediction models were proposed for dynamic environments with TR. • The thermal experience of occupants might play essential roles in TR environments. [ABSTRACT FROM AUTHOR]

Highlights • Meteorological parameters were collected in an urban park during winter. • The relationship between thermal sensation and comfort were investigated. • Outdoor human thermal comfort varied with landscape in urban park. • UTCI was the most suitable index to evaluate the human thermal comfort in Xi'an. • The neutral PET and the neutral UTCI ranged within 13.3–23.6℃ and 14.9–23.2℃. Abstract Urban parks play significant roles in improving urban microclimate and reducing urban heat islands. Using microclimatic monitoring and a questionnaire survey of thermal comfort, this study investigated thermal comfort during winter in different urban park landscapes in Xi'an, China. Results indicated that: 1) Human comfort was strongly related to their thermal sensation; 2) In winter, global radiation was the most important factor affecting human comfort, followed by air temperature and relative humidity, and wind speed was the least important factor; 3) Landscape type and components had significant impacts on the outdoor thermal environment and human thermal comfort; 4) Residents desired intense solar radiation and higher air temperature in winter, but were not sensitive to wind speed or relative humidity; 5) Psychological factors had particular effects on human thermal sensation, and 6) Universal Thermal Climate Index (UTCI) was the most suitable index to evaluate outdoor human thermal comfort in Xi'an. The neutral Physiological Equivalent Temperature (PET) and the neutral UTCI ranged within 13.3–23.6℃ and 14.9–23.2℃, respectively. These results could serve as theoretical baselines and technical references for urban park design when considering the construction of sustainable cities. [ABSTRACT FROM AUTHOR]

A concept known as ‘nudge’ has recently received attention in many application domains. It implies influencing the behavior and decision-making of individuals by making indirect suggestions through the presentation of adequate information. We apply such a perspective to improve the value of a space. It can be measured by the number of visitors, and the predicted thermal sensation is considered as information offered to potential visitors. In the present study, we explain how to generate the information required for a successful nudge. This information must be specifically tailored towards personalized characteristics, rather than a one-fits-all approach. This study presents a new data-driven method for predicting individuals' thermal sensation by formulating the effect of both measured (thermal) and non-measured factors on thermal sensation votes. The proposed model is explicitly encoded based on a major premise that “different individuals have different thermal sensation characteristics; however, all individuals also have a common trend.” The inference model uses a Bayesian approach, and is hierarchically structured to represent dependencies across model parameters of the personalized characteristics of individual-level and the typical trend of group-level thermal sensations. The Markov chain Monte Carlo approach is used to approximate the posterior distribution and draw inferences on the model parameters. The results, based on data collected from outdoor spaces, show that the proposed model provides accurate predictions for personalized thermal sensation and improves the efficiency of parameter estimates. Our approach provides fresh insight into statistical models for predicting thermal sensation. [ABSTRACT FROM AUTHOR]