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Context: Little information exists regarding what exertional heatstroke (EHS) survivors know and believe about EHS best practices. Understanding this would help clinicians focus educational efforts to ensure survival and safe return-to-play following EHS., Objective: We sought to better understand what EHS survivors knew about EHS seriousness (eg, lethality and short- and long-term effects), diagnosis and treatment procedures, and recovery., Design: Multiyear cross-sectional descriptive design., Setting: An 11.3-km road race located in the Northeastern United States in August 2022 and 2023., Patients or Other Participants: Forty-two of 62 runners with EHS (15 women and 27 men; age = 33 ± 15 years; pretreatment rectal temperature [TREC] = 41.5°C ± 0.9°C)., Interventions: Medical professionals evaluated runners requiring medical attention at the finish line. If they observed a TREC of ≥40°C with concomitant central nervous system dysfunction, EHS was diagnosed, and patients were immersed in a 189.3-L tub filled with ice water. Before medical discharge, we asked EHS survivors 15 questions about their experience and knowledge of select EHS best practices. Survey items were piloted and validated by experts and laypersons a priori (content validity index of ≥0.88 for items and scale)., Main Outcome Measures: Survey responses., Results: Sixty-seven percent (28/42) of patients identified EHS as potentially fatal, and 76% (32/42) indicated that it negatively affected health. Seventy-nine percent (33/42) correctly identified TREC as the best temperature site to diagnose EHS. Most patients (74%, 31/42) anticipated returning to normal exercise within 1 week after EHS; 69% (29/42) stated that EHS would not impact future race participation. Patients (69%, 29/42) indicated that it was important to tell their primary care physician about their EHS., Conclusions: Our patients were knowledgeable on the potential seriousness and adverse health effects of EHS and the necessity of TREC for diagnosis. However, educational efforts should be directed toward helping patients understand safe recovery and return-to-play timelines following EHS., (© by the National Athletic Trainers' Association, Inc.)

Recently, the incidence of heat-related illnesses has exhibited a steadily upward trend, which is closely associated with several environmental factors such as climate change and air pollution. The progression of heat-related illnesses is a continuous process and can progress to the terminal period when it transforms into heat stroke, the most severe form. Heat stroke is markedly by a core body temperature above 40°C and central nervous system dysfunction. Current knowledge suggests that the pathogenesis of heat stroke is complex and varied, including inflammatory response, oxidative stress, cell death, and coagulation dysfunction. This review consolidated recent research progress on the pathophysiology and pathogenesis of heat stroke, with a focus on the related molecular mechanisms. In addition, we reviewed common strategies and sorted out the drugs in various preclinical stages for heat stroke, aiming to offer a comprehensive research roadmap for more in-depth researches into the mechanisms of heat stroke and the reduction in the mortality of heat stroke in the future., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

We described an 82-year-old man who was taken to our emergency department after being found unconscious. His electrocardiogram (ECG) showed ST-segment elevation in leads V4-V6 and cardiac troponin I (cTnI) was abnormally elevated. In addition to ECG and cTnI changes, this patient was combined with unconsciousness, high fever, abnormal liver function, acute renal failure, and rhabdomyolysis. The initial diagnosis was heat stroke, so cooling measures were initiated immediately, but a concurrent myocardial infarction was suspected. Meanwhile, emergency coronary angiography was performed, but no severe coronary stenosis or thrombosis was found. We first evaluated quantitative flow ratio (QFR) and coronary angiography-derived index of microvascular resistance (ca-IMR) in patients with heat stroke. Ca-IMR was 260 mmHg*s/m in the left circumflex artery, indicating the presence of coronary microvascular dysfunction (CMD). After several days of treatment, the patient recovered from multiple organ damage. Therefore, ECG and troponin results should be interpreted carefully in patients with high fever and coma during high temperature seasons., Competing Interests: Declaration of competing interest All authors declared no conflicts of interest., (Copyright © 2024 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.)

The objective of this study was to analyze the changes of activated partial thromboplastin time (APTT) and D-dimer in severe heatstroke (HS) patients and their value in identifying HS patients and to analyze clinical features and early laboratory test results of heat-related illnesses. Forty-five patients with heat-related illnesses who were admitted to the Department of Emergency and Intensive Care Medicine of Suining Central Hospital from June 2022 to April 2023 were retrospectively analyzed. Patients were divided into 3 groups based on their clinical diagnosis: classic HS group, exertional HS group, and control group. General date and laboratory test results were collected, especially APTT and D-dimer. The receiver operating characteristic curve was used to analyze D-dimer and APTT. : There were differences in gender distribution among the 3 groups. Exertional HS was dominated by male patients, and classic HS was dominated by elderly patients. Binary logistic regression analysis of coagulation index showed a significant correlation between D-dimer and APTT and HS. The receiver operating characteristic curve results showed that APTT and D-dimer had high sensitivity and specificity in the identification of HS with an area under the curve (AUC) of 0.846, sensitivity of 97%, and specificity of 58.3% for APTT and an AUC of 0.861, sensitivity of 72%, and specificity of 91.7% for D-dimer (D-dimer + APTT [AUC, 0.929; sensitivity, 81.8%-91.7%; P < .001]). : The mortality rate of HS is high, and early diagnosis is particularly important. APTT and D-dimer may be used as markers assisting in identifying HS., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Abstract: This article concisely overviews heat-related illnesses, emphasizing their significant impact on public health. It explores the pathophysiology of conditions ranging from mild heat cramps to life-threatening heat stroke, highlighting key heat transfer mechanisms and the importance of environmental factors. Differential diagnosis considerations, prevention strategies, and nursing implications are discussed, underscoring the need for prompt recognition and intervention in managing these conditions., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: The frequency and intensity of heat waves are currently increasing due to climate change. Hence more cases of heat illness are being observed, a potentially life-threatening disease, which requires rapid and expert management., Objectives: An overview of the pathophysiology and acute management of heat illness is presented., Materials and Methods: Analysis and evaluation of important, recently published contributions, studies, and reviews regarding heat illness without claim for completeness or fulfilling the criteria for a 'systematic meta-analysis'. Presentation of a recommended clinical-practical classification and management of heat illness in emergency departments or intensive care units., Results: The manifestation of heat illness arising from prolonged exposure to heat prevaries (heat cramps, heat edema, heat exhaustion, heat stroke). The main pathophysiologic mechanisms are disruption of thermoregulation, peripheral vasodilation of the skin surface, hypoperfusion of visceral organs, and brain, and cardiac stress. Uncompensated heat stress can result in multiorgan dysfunction/failure syndrome due to the initiation of cytokine pathways, specifically in at-risk and/or chronically ill patients. The manifestation of uncompensated heat stroke is associated with a hospital mortality > 50%. Rapid identification, classification and targeted management are crucial for the outcome, in particular the initiation of adequate cooling measures., Conclusion: In the future, increasing numbers of patients suffering from prolonged heat exposure will require treatment in emergency departments and intensive care units. Sufficient professional knowledge regarding pathophysiology and management are decisive for successful therapy. Hence, the topic heat illness should be implemented in training and education., (© 2023. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Abstract: A 23-year-old woman completing her first marathon collapsed near the finish line at 4 hours 6 min with a rectal temperature of 41.8°C. She was in good health before the race with no recent illness, had completed a full training program, and was taking no medications or supplements. On the initial exam, she was unconscious with a response to painful stimulus, spontaneous breathing, rapid pulse, eyes closed, fully dilated pupils, poor muscle tone, and pale skin that was warm to touch. The medical team initiated whole-body cooling using rapidly rotating ice water towels and ice packs placed in the neck, axilla, and groin. She developed echolalia during active cooling. About 20 minutes into the cooling procedure, she "woke up," was able to answer questions coherently, and her pupils were normal size and reactive. She was discharged home with instructions to follow-up in 2 d for evaluation and blood chemistry testing., (Copyright © 2024 by the American College of Sports Medicine.)

Objectives: Exertional heat stroke (EHS) remains a significant health concern while training in hot environments, prompting the development of noninvasive wearable technology for monitoring estimated core temperature (ECT). The objective of this study was to review the effectiveness of an ECT device during elite military training by providing a case series of individuals who developed EHS., Methods: This is a retrospective study of EHS cases during high-intensity training while wearing the ECT device, Zephyr Bioharness TM . Data was collected from January 2021 through September 2021 at the Air Force Special Warfare Training pipeline in San Antonio, TX. Rectal temperatures of EHS diagnoses, defined by central nervous system (CNS) dysfunction and rectal temperature approaching or >40°C (104°F), were compared to ECT reading via Zephyr Bioharness TM . Incidence rates and psychometric properties were calculated using R package., Results: A total of 47,058 daily peak ECT measurements were collected among 1,364 trainees. A total of 499 trainees flagged as potential EHS by Zephyr Bioharness TM reading >39.7°C (103.5°F). The incidence of confirmed EHS was 0.8/1000 person-months. Of the 10 confirmed EHS cases (9 males, 1 female; age = 23.4 ± 2.7 yrs; BMI = 25 ± 2; body fat = 13 ± 5%), 8 trainees had a peak ECT reading below 39.7°C which resulted in a sensitivity of 20%, specificity of 98.9%, positive likelihood ratio (LR) of 18.93 (95% Confidence Interval [CI] 5.5-65.6), and a negative LR of 0.81 (95% CI 0.6-1.1)., Conclusion: ECT had substantial false positive and negative rates. Further studies are needed to validate this technology in other populations, and the algorithm used in this device needs to be refined to better capture the environmental and physical requirements in the special operations population.

Risk of exertional heat stroke (EHS) is an ongoing challenge for United States military personnel, for athletes and for individuals with occupational stressors that involve prolonged activity in hot environments. Higher body mass index (BMI) is significantly associated with increased risk for EHS in activity duty U.S. Soldiers. During exercise, heat is generated primarily by contracting skeletal muscle (and other metabolically active body mass) and dissipated based on body surface area (BSA). Thus, in compensable environments, a higher BSA·mass -1 may be a benefit to heat dissipation and decrease the risk of EHS. The purpose of the present analysis was to test the hypothesis that BSA·mass -1 ratio is an important biophysical characteristic contributing to the risk of EHS. We employed a matched case-control approach, where each individual with a diagnosis of EHS was matched to five controls who were never diagnosed with EHS but were in the same unit and had the same job title. We used a multivariate conditional logistic regression model including variables of BSA·mass -1 , sex, age, military rank, and race. BSA·mass -1 significantly predicted EHS risk ( P = 0.006), such that people with higher BSA·mass -1 were at lower risk of developing EHS when controlling for other potential factors such as age and race. This relationship persisted after adjustment for other anthropometric measures of body size including weight, BMI, and BSA. These data suggest that biophysical factors play an important role in EHS risk, particularly in a healthy military-aged cohort of men and women. NEW & NOTEWORTHY With the impacts of climate change yielding higher average ambient temperatures over time, the incidence of EHS for individuals participating in outdoor activities may consequently increase. With the larger sample size in this study compared with prior research in this field, we were able to use various methods that had not been applied before. For example, we were able to mutually adjust for different measurements of body size to understand which metric had the highest association with EHS risk. Understanding factors that may be modifiable may be important for developing interventions to counteract the increased risk of EHS associated with climate change.

Background: Climate change is leading to more extreme heat events in temperate climates that typically have low levels of preparedness. Our objective was to describe the characteristics, treatments, and outcomes of adults presenting to hospitals with heatstroke during BC's 2021 heat dome., Methods: We conducted a review of consecutive adults presenting to 7 hospitals in BC's Lower Mainland. We screened the triage records of all patients presenting between June 25th and 30th, 2021 for complaints related to heat, and reviewed the full records of those who met heatstroke criteria. Our primary outcome was in-hospital mortality. We used Mann-Whitney U tests and logistic regression to investigate associations between patient and treatment factors and mortality., Results: Among 10,247 consecutive presentations to urban hospitals during the extreme heat event, 1.3% (139; 95% confidence intervals [CI] 1.1-1.6%) met criteria for heatstroke. Of heatstroke patients, 129 (90.6%) were triaged into the two highest acuity levels. Patients with heatstroke had a median age of 84.4 years, with 122 (87.8%) living alone, and 101 (84.2%) unable to activate 911 themselves. A minority (< 5, < 3.6%) of patients presented within 48 h of the onset of extreme heat. Most patients (107, 77.0%) required admission, and 11.5% (16) died in hospital. Hypotension on presentation was associated with mortality (odds ratio [OR] 5.3)., Interpretation: Heatstroke patients were unable to activate 911 themselves, and most presented with a 48-h delay. This delay may represent a critical window of opportunity for pre-hospital and hospital systems to prepare for the influx of high-acuity resource-intensive patients., (© 2023. The Author(s).)

Background: In several situations, spurious results are observed in the use of hematology analyzers including pseudothrombocytosis caused by part of the cytoplasm of abnormal cells which was reported in leukemic blasts, monoblasts, or lymphoblasts., Methods and Results: Here, we report a rare case of pseudothrombocytosis caused by mature leukocyte fragments associated with heatstroke. It was identified by the peripheral blood smear and obvious difference between the PLT-F (fluorescence) and I (impedance) channel., Conclusions: Observation of peripheral blood smears and determination on the PLT-F channel can identify this interference caused by leukocyte fragments in heatstroke.

Introduction: The recommended treatment for exertional heat stroke is immediate, whole-body immersion in < 10 °C water until rectal temperature (T re ) reaches ≤ 38.6 °C. However, real-time T re assessment is not always feasible or available in field settings or emergency situations. We defined and validated immersion durations for water temperatures of 2-26 °C for treating exertional heat stroke., Methods: We compiled data for 54 men and 18 women from 7 previous laboratory studies and derived immersion durations for reaching 38.6 °C T re . The resulting immersion durations were validated against the durations of cold-water immersion used to treat 162 (98 men; 64 women) exertional heat stroke cases at the Falmouth Road Race between 1984 and 2011., Results: Age, height, weight, body surface area, body fat, fat mass, lean body mass, and peak oxygen uptake were weakly associated with the cooling time to a safe T re of 38.6 °C during immersions to 2-26 °C water (R 2 range: 0.00-0.16). Using a specificity criterion of 0.9, receiver operating characteristics curve analysis showed that exertional heat stroke patients must be immersed for 11-12 min when water temperature is ≤ 9 °C, and for 18-19 min when water temperature is 10-26 °C (Cohen's Kappa: 0.32-0.75, p < 0.001; diagnostic odds ratio: 8.63-103.27)., Conclusion: The reported immersion durations are effective for > 90% of exertional heat stroke patients with pre-immersion T re of 39.5-42.8 °C. When available, real-time T re monitoring is the standard of care to accurately diagnose and treat exertional heat stroke, avoiding adverse health outcomes associated with under- or over-cooling, and for implementing cool-first transport second exertional heat stroke policies., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Heat-related illness commonly affects adolescent patients, especially as summer approaches and global temperature extremes worsen. Basic counseling on sunburn prevention can decrease the risk for future malignancies, and rapidly preventing, identifying, and treating heat stroke can prevent severe morbidity and mortality. This article will review the epidemiology of exertional heat-related illness and the variations in presentations and pathology, from heat rash and sunburn to heat exhaustion and heat stroke. By the end of this review clinicians should be able to identify and treat different heat-related illnesses in adolescents and potentially save a life. [ Pediatr Ann . 2024;53(1):e17-e21.] .

Annual rates of heat illness and heat-related deaths have been increasing across the United States as more regions of the country have been experiencing heat waves of extreme ambient temperatures of prolonged durations. According to the Centers for Disease Control and Prevention, heat illnesses have become the leading cause of weather-related deaths. This article critiques and describes the findings of a systematic review by C. Rublee et al. (2021). The review was conducted to develop an evidence-based algorithm specific for management of heatstroke in the emergency department with implications for improving recognition, initiating rapid cooling, and providing supportive care to reduce patient mortality and morbidity., Competing Interests: Disclosure: The authors report no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Rationale: Heat-related illnesses have protean manifestations that can mimic other life-threatening conditions. The diagnosis of heat stroke requires a high index of suspicion if the patient has been exposed to a high-temperature environment. Central nervous system dysfunction is a cardinal feature. Strict adherence to temperature criteria can potentially lead to misdiagnosis., Patient Concerns: A 37-year-old construction worker was brought in by his wife and coworker due to a sudden loss of consciousness while resting after completing his work., Diagnoses: Due to challenges faced during the coronavirus disease 2019 pandemic, as well as language barriers, a detailed history from the coworker who witnessed the patient's altered sensorium was not available. He was initially suspected of having encephalitis and brainstem stroke. However, subsequent investigations revealed multiorgan dysfunction with a normal brain computed tomography and cerebral computed tomography angiogram. In view of the multiple risk factors for heat stroke, pupillary constriction, and urine color suggestive of rhabdomyolysis, a diagnosis of heat stroke was made., Interventions: Despite delayed diagnosis, the patient's multiorgan dysfunction recovered within days with basic supportive care., Outcomes: There were no noticeable complications on follow-up 14 months later., Lessons: Heat stroke can be easily confused with other neurological pathologies, particularly if no history can be obtained from the patient or informant. When approaching a comatose patient, we propose that serum creatinine kinase should be considered as an initial biochemical screening test., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2023 the Author(s). Published by Wolters Kluwer Health, Inc.)

Heatstroke (HS), a severe condition, can develop multiple organ dysfunction syndrome and death. However, at present, no early reliable index exists for risk stratification and prognosis. von Willebrand factor (vWF), a marker of vascular endothelial injury, is a key regulatory target of inflammation and coagulation, which is closely associated with the pathogenesis of HS. vWF was reported as a prognostic marker in several infectious and noninfectious severe illness such as COVID-19, sepsis, and trauma. Although early increased level of vWF is seen in HS, the relationship between vWF and mortality is to be elucidated. Clinical data of patients with HS in a tertiary hospital were recorded and analyzed. It was shown that plasma vWF concentrations at admission were significantly increased in the nonsurvivors (351% ± 105%) compared with survivors (278% ± 104%, p  = 0.021). After multivariate logistic regression analysis it was shown that vWF (odds ratio [OR] = 1.010; 95% confidence interval [CI], 1.002-1.18; p  = 0.017), hemoglobin (Hb) (OR = 0.954; 95% CI, 0.931-0.979; p  < 0.001), and hematocrit (HCT) in blood (OR = 0.859; 95% CI, 0.790-0.934; p  < 0.001) were independent factors of in-hospital mortality in HS. The nomogram based on vWF and Hb was constructed in patients with HS. The area under curve under the receiver operating characteristic of this prediction model was 0.860 (95% CI, 0.773-0.923) and cutoff was 0.15, with Youden index 0.5840, which were not significantly different to sequential organ failure assessment ( p  = 0.0644), Acute Physiology and Chronic Health Evaluation II (APACHE II) ( p  = 0.7976), and systemic inflammatory response syndrome (SIRS) scores ( p  = 0.3274). The prediction model that integrated vWF and Hb showed a better predicting efficiency than single variable, and a higher specificity (81.48%) than APACHE II (72.84%) and SIRS (72.84%) scores. In summary, vWF, as an independent risk factor for in-hospital mortality, combined with Hb, could effectively prognosis the mortality in HS patients at early stage.

We employed wearable multimodal sensing (heart rate and triaxial accelerometry) with machine learning to enable early prediction of impending exertional heat stroke (EHS). US Army Rangers and Combat Engineers (N = 2,102) were instrumented while participating in rigorous 7-mile and 12-mile loaded rucksack timed marches. There were three EHS cases, and data from 478 Rangers were analyzed for model building and controls. The data-driven machine learning approach incorporated estimates of physiological strain (heart rate) and physical stress (estimated metabolic rate) trajectories, followed by reconstruction to obtain compressed representations which then fed into anomaly detection for EHS prediction. Impending EHS was predicted from 33 to 69 min before collapse. These findings demonstrate that low dimensional physiological stress to strain patterns with machine learning anomaly detection enables early prediction of impending EHS which will allow interventions that minimize or avoid pathophysiological sequelae. We describe how our approach can be expanded to other physical activities and enhanced with novel sensors.

Increased intestinal permeability during exertion and subsequent leakage of bacteria into circulation is hypothesized to accelerate exertional heat stroke (EHS) onset and/or exacerbate EHS severity. To provide proof of concept for this theory, we targeted intestinal microbiota via antibiotic prophylaxis and determined whether vancomycin would delay EHS onset and/or mitigate EHS severity and mortality rates using a mouse model of EHS. Mice were 1 ) designated as EHS or Exercise Control (ExC) and 2 ) given 7 days of vancomycin (VEHS, VExC) or untreated water (EHS, ExC) before EHS/Exercise. Following EHS/ExC, mice were euthanized immediately (0 h) or returned to their home cage (25°C) and euthanized after 3 h or 24 h. VEHS mice exhibited reduced abundance and altered composition of fecal bacteria (with notable decreases in genera within orders Clostridiales and Bacteroidales ); increased water consumption, lower core temperature (T C ) before and during heating (T CMax ), lower circulating markers of organ damage and inflammation at 24 h; and reduced hepatic activation of stress pathways at 0 and 3 h compared with EHS mice. Vancomycin-induced alterations to the intestinal microbiota likely influenced EHS outcomes, but it is unconfirmed whether this is due to attenuated bacterial leakage into circulation or other (in)direct effects on physiology and behavior (e.g., decreased T C, increased water consumption). To our knowledge, this is the first study quantitating antibiotic effects in conscious/unanesthetized, exertional HS animals. NEW & NOTEWORTHY Vancomycin prophylaxis lowered core temperature before and during EHS, mitigated EHS-associated rise of hepatic biomarkers and cytokines/chemokines in circulation (particularly at 24 h), and corresponded to inhibited phosphorylation of hepatic c-Jun NH 2 -terminal kinase on Threonine 183/Tyrosine 185 at 0 and 3 h in conscious, unanesthetized mice. However, vancomycin also induced cecal enlargement suggesting its off-target effects could limit its utility against EHS.

We report the case of a 52-year-old marathon runner admitted to our emergency department for exertional heat stroke (EHS). The electrocardiogram (ECG) showed a supraventricular tachycardia, probably an atrial flutter with 2:1 block, conducted with left bundle branch block. After 10 minutes of aggressive fluid management and rapid external cooling, the ECG returned to normal. As the high-sensitivity cardiac troponin I was elevated, coronary angiography and an electrophysiological study were performed, revealing normal coronary arteries and excluding inducible arrhythmias. As reported in the current literature, our findings confirm that the electrocardiographic changes and elevation of cardiac markers in EHS do not reflect cardiac ischemia, but rather a myocardial injury due to the pathophysiological response to dehydration and hyperthermia, which markedly impaired stroke volume and cardiac output. EHS is a life-threatening condition with a complex pathophysiology caused by thermoregulatory failure. Diagnosis is not always straightforward, but early recognition and timely management (the "golden hour") with rapid cooling and intravenous fluids are crucial to prevent irreversible and fatal organ damage. EHS is defined by a rectal temperature > 40.5 °C with symptoms or signs of neurological dysfunction, such as confusion, drowsiness, or seizures, which can rapidly worsen with delirium, coma, and cardiac arrest. With this case report, we want to remind emergency physicians that early diagnosis and appropriate management of EHS can avoid death and inappropriate treatment. (www.actabiomedica.it).

Objective: To investigate the clinical significance of early troponin I (TnI) level in the prognosis of severe heat stroke., Methods: Clinical data of 131 patients with severe heat stroke in the intensive care unit (ICU) of the Affiliated Changzhou NO.2 People's Hospital of Nanjing Medical University (study dataset) and ICU 67 patients with severe heat stroke in Jintan First People's Hospital of Changzhou (validation dataset) were retrospectively analyzed from June 2013 to September 2022. The patients were divided into survival group and death group according to 30-day outcomes. TnI was collected within 24 hours after admission to the emergency department. Cox regression analysis was performed to analyze the risk factors of severe heat stroke death. Spearman correlation test was used to analyze the correlation between TnI and heart rate, and peripheral systolic blood pressure. The receiver operator characteristic curve (ROC curve) was drawn to evaluate the predictive value of TnI for death in patients with severe heat stroke. Decision curve analysis (DCA) was conducted to assess the clinical net benefit rate of TnI prediction. Grouping by TnI cut-off value, Kaplan-Meier survival curve was used to analyze 30-day cumulative survival. Sensitivity analysis included modified Possion regression, E-value, and subgroup forest map was used to evaluate the mortality risk of TnI in different populations. External dataset was used to verify the predictive value of TnI., Results: The death group had significantly higher TnI compared to the survival group [μg/L: 0.623 (0.196, 1.510) vs. 0.084 (0.019, 0.285), P < 0.01]. Multivariate Cox regression analysis after adjusting for confounding factors showed that TnI was an independent risk factor for death [hazard ratio (HR) = 1.885, 95% confidence interval (95%CI) was 1.528-2.325,P < 0.001]. Spearman correlation test showed that TnI was positively correlated with heart rate (r = 0.537, P < 0.001) and negatively correlated with peripheral systolic blood pressure (r = -0.611, P < 0.001). ROC curve showed that the area under the curve (AUC) of the TnI (0.817) was better than that of the acute physiology and chronic health evaluation II (APACHE II, 0.756). The DCA curve showed that the range of clinical net benefit rate of TnI (6.21%-20.00%) was higher than that of APACHE II score (5.14%-20.00%). Kaplan-Meier survival curve showed that patients in the low-risk group (TnI ≤ 0.106) had a significantly higher 30-day survival rate than that in the high-risk group (TnI > 0.106) group (Log-Rank test: χ 2 = 17.350, P < 0.001). Modified Possion regression with adjustment for confounding factors showed that TnI was still an independent risk factor for death in patients with severe heat stroke [relative risk (RR) = 1.425, 95%CI was 1.284-1.583, P < 0.001]. The E-value was 2.215. The subgroup forest plot showed that the risk factors of TnI were obvious in male patients and patients ≤ 60 years old (male: HR = 1.731, 95%CI was 1.402-2.138, P < 0.001; ≤ 60 years old: HR = 1.651, 95%CI was 1.362-2.012, P < 0.001). In the validation dataset, ROC curve analysis showed that the AUC (0.836) of TnI predicting the prognosis of severe heat stroke was still higher than the APACHE II score (0.763)., Conclusions: Early elevation of TnI is a high-risk factor for death in patients with severe heat stroke, and it has a good predictive value for death.

Heatstroke (HS) is a life-threatening injury requiring neurocritical care which could lead to central nervous system dysfunction and severe multiple organ failure syndrome. The cell-cell adhesion and cell permeability are two key factors for characterizing HS. To investigate the process of HS, a biochip-based electrical model was proposed and applied to HS. During the process, the value of TEER is associated with cell permeability and C I which represents cell-cell adhesion decreases that are consistent with the reduction in cell-cell adhesion and cell permeability characterized by proteins (occludin, VE-Cadherin and ZO-1) and RNA level. The results imply that the model can be used to monitor the biological process and other biomedical applications.

BACKGROUND Coma has been considered as a valuable symptom of heatstroke. This study aimed to evaluate the role of the Glasgow Coma Scale (GCS) as an indicator of prognosis of patients with heatstroke. MATERIAL AND METHODS From Jan 1st, 2013 to Dec 31st, 2020, the clinical courses of 257 heatstroke patients from 3 medical centers in Guangdong, China, were observed. Diagnosis of heatstroke was made according to Expert Consensus in China. GCSs were calculated on the 1st, 3rd, and 5th days after admission to intensive care units (ICUs). GCS £8, as a coma criterion, was employed to predict the outcomes. RESULTS Seventy-five patients (29.18%) were comatose at admission. Twenty-seven (10.50%) patients, including 24 (24/75, 32.00%) coma patients and 3 (3/182,1.65%) non-coma patients died during ICU stay (P<0.0001). Patients with GCS ≤8 had a 2-fold higher risk of death as compared with those with GCS >8. The area under curves (AUCs) of GCSs on the 1st, 3rd, and 5th days to predict mortality were 0.81 (0.70-0.91), 0.91 (0.84-0.98), and 0.91 (0.82-0.99), respectively. Each additional 1 year of age, 1/min of respiratory rate (RR), and 1% of hematocrit (HCT) increased the risk of death of coma patients by 3%, 6%, and 4%, respectively (all P≤0.05). Patients with improving GCSs had lower mortality rates than non-improving patients (5.71% vs 55.00%, P<0.0001) within 5 days after admission. CONCLUSIONS GCS ≤8 at admission predicted worse outcomes in heatstroke patients, which possibly enhanced the risks of death for other factors, including age, RR, and HCT.

Thermoregulation keeps the normal body temperature of humans at approximately 37 °C. However, as a result of heat load - both endogenous and exogenous heat - it can occur that the body is unable to dissipate excess heat, leading to an increase in the core body temperature. This can result in various heat illnesses, ranging from mild, non-life-threatening conditions, such as heat rash, heat edema, heat cramps, heat syncope and exercise associated collapse to life-threatening conditions, namely exertional heatstroke and classic heatstroke. Exertional heatstroke is the result of strenuous exercise in a (relatively) hot environment, whereas classic heatstroke is caused by environmental heat. Both forms result in a core temperature of > 40 °C in combination with a lowered or altered consciousness. Early recognition and treatment are critical in reducing morbidity and mortality. Cornerstone of treatment is cooling.

A 14-year-old runner indigenous to the tropics collapsed during his first 10-km race in a hot and humid climate. Dizziness, stumbling, and loss of consciousness were symptoms of exertional heat stroke. Two days postcollapse, blood tests revealed elevated hepatic transaminases consistent with hepatic injury. We discuss the return-to-competition progression, which included a gradual increase in exercise duration, initially in a cool and then in a tropical climate, and 2 field-based (wet-bulb globe temperature > 29.0°C) running evaluations that simulated the environmental conditions and training intensity the athlete would encounter in his sport. The thermoregulatory results guided the training progression, his tolerance to running in the heat improved, blood values normalized, and he was cleared to compete in a tropical climate. This exploration case report presents a novel field-based protocol that replicates the physiological demands of training in the tropics to evaluate thermoregulatory responses during exercise-heat stress in young runners after exertional heat stroke to facilitate a safe return to competition., (© by the National Athletic Trainers' Association, Inc.)

Competing Interests: Competing interests: None declared.

Abstract: Exertional heat stroke is a true medical emergency with potential for organ injury and death. This consensus statement emphasizes that optimal exertional heat illness management is promoted by a synchronized chain of survival that promotes rapid recognition and management, as well as communication between care teams. Health care providers should be confident in the definitions, etiologies, and nuances of exertional heat exhaustion, exertional heat injury, and exertional heat stroke. Identifying the athlete with suspected exertional heat stroke early in the course, stopping activity (body heat generation), and providing rapid total body cooling are essential for survival, and like any critical life-threatening situation (cardiac arrest, brain stroke, sepsis), time is tissue. Recovery from exertional heat stroke is variable and outcomes are likely related to the duration of severe hyperthermia. Most exertional heat illnesses can be prevented with the recognition and modification of well-described risk factors ideally addressed through leadership, policy, and on-site health care., (Copyright © 2023 by the American College of Sports Medicine.)

The significance of calcitoninogen detection among inpatients was discussed by analyzing the clinical characteristics of severe heatstroke (HS). HS patients who were admitted to the Second Hospital of Nantong University, Jiangsu Province, China, between July 1, 2015, and October 30, 2020, were reviewed. Patients' clinical characteristics and laboratory data were recorded, and they were divided into three groups, that is, a control group (heat cramps and heat exhaustion), an exertional HS (EHS) group, and a classical HS (CHS) group to compare the differences among them. Receiver operating characteristic (ROC) curves were plotted to evaluate patients' clinical utility. (1) The body temperatures in the EHS and CHS groups were significantly higher than in the control group (all p  < 0.05). (2) The D-dimer (DD), procalcitonin (PCT), and Acute Physiology and Chronic Health Evaluation (APACHE) II score of the EHS group were significantly higher compared with the control and CHS groups (all p  < 0.05); the platelets (PLT), C-reactive protein (CRP), blood sodium (Na), and intravenous glucose (GLU) of the EHS group were lower than in the control and CHS groups (all p  < 0.05). (3) The ROC curve analysis showed the performance results for DD (area under the curve [AUC] 0.670, 95% confidence interval [CI] 0.547-0.777), PCT (AUC 0.705, 95% CI 0.584-0.808), and PLT (AUC 0.791, 95% CI 0.677-0.879). The sensitivity was 40.48%, 100%, and 73.81%, and the specificity was 96.43%, 32.14%, and 78.57%, respectively. Using three combined analyses, an elevated AUC of 0.838, 95% CI 0.731-0.916, with a sensitivity of 71.43% and a specificity of 85.71%, respectively, was revealed. Patients in the EHS group had higher DD, PCT, and APACHE II values, whereas PLT, CRP, Na, and GLU were reduced. The apparent decrease in the PLT, as well as the increase in PCT and DD values, could be considered as early sensitivity indicators of severe HS. A combined test of these three indicators presented significant diagnostic value for detecting severe cases of HS.

Background: The incidence of heat emergencies, including heat stroke and heat exhaustion, have increased recently due to climate change. This has affected global health and has become an issue of consideration for human health and well-being. Due to overlapping clinical manifestations with other diseases, and most of these emergencies occurring in an elderly patient, patients with a comorbid condition, or patients on poly medicine, diagnosing and managing them in the emergency department can be challenging. This study assessed whether an educational training on heat emergencies, defined as heat intervention in our study, could improve the diagnosis and management practices of ED healthcare providers in the ED setting., Methods: A quasi-experimental study was conducted in the EDs of four hospitals in Karachi, Pakistan. Eight thousand two hundred three (8203) patients were enrolled at the ED triage based on symptoms of heat emergencies. The pre-intervention data were collected from May to July 2017, while the post-intervention data were collected from May to July 2018. The HEAT intervention, consisting of educational activities targeted toward ED healthcare providers, was implemented in April 2018. The outcomes assessed were improved recognition-measured by increased frequency of diagnosing heat emergencies and improved management-measured by increased temperature monitoring, external cooling measures, and intravenous fluids in the post-intervention period compared to pre-intervention., Results: Four thousand one hundred eighty-two patients were enrolled in the pre-intervention period and 4022 in the post-intervention period, with at least one symptom falling under the criteria for diagnosis of a heat emergency. The diagnosis rate improved from 3% (n = 125/4181) to 7.5% (n = 7.5/4022) (p-value < 0.001), temperature monitoring improved from 0.9% (n = 41/4181) to 13% (n = 496/4022) (p-value < 0.001) and external cooling measure (water sponging) improved from 1.3% (n = 89/4181) to 3.4% (n = 210/4022) (p-value < 0.001) after the administration of the HEAT intervention., Conclusion: The HEAT intervention in our study improved ED healthcare providers' approach towards diagnosis and management practices of patients presenting with health emergencies (heat stroke or heat exhaustion) in the ED setting. The findings support the case of training ED healthcare providers to address emerging health issues due to rising temperatures/ climate change using standardized treatment algorithms., (© 2023. The Author(s).)

Exertional heat stroke (EHS) remains a persistent threat for individuals working or playing in the heat, including athletes and military and emergency service personnel. However, influence of biological sex and/or body mass index (BMI) on the risk of EHS remain poorly understood. The purpose of this study was to retrospectively assess the influence of sex and BMI on risk of EHS in the active-duty US Army. We analyzed data from 2016 to 2021, using a matched case-control approach, where each individual with a diagnosis of EHS was matched to five controls based on calendar time, unit ID, and job category, to capture control individuals who were matched to EHS events by location, time, and activity. We used a multivariate logistic regression model mutually adjusted for sex, BMI, and age to compare 745 ( n = 61 F) individuals (26 ± 7 yr) with a diagnosed EHS to 4,290 ( n = 384 F) case controls (25 ± 5 yr). Group average BMI were similar: 26.6 ± 3.1 (EHS) and 26.5 ± 3.6 kg/m 2 (CON). BMI was significantly ( P < 0.0001) associated with higher risk of EHS with a 3% increase in risk of EHS for every unit increase in BMI. Notably, sex was not associated with any difference in risk for EHS ( P = 0.54). These data suggest that young healthy people with higher BMI have significantly higher risk of EHS, but, contrary to what some have proposed, this risk was not higher in young women.

Heatstroke is a concern during sudden heat waves. We designed and prototyped an Internet of Things system for heatstroke prevention, which integrates physiological information, including deep body temperature (DBT), based on the dual-heat-flux method. A dual-heat-flux thermometer developed to monitor DBT in real-time was also evaluated. Real-time readings from the thermometer are stored on a cloud platform and processed by a decision rule, which can alert the user to heatstroke. Although the validation of the system is ongoing, its feasibility is demonstrated in a preliminary experiment.

Introduction: The capability of male mice to exercise in hot environments without succumbing to exertional heat stroke (EHS) is markedly blunted compared to females. Epidemiological evidence in humans and other mammals also suggests some degree of greater vulnerability to heat stroke in males compared to females. The origins of these differences are unknown, but testosterone has previously been shown to induce faster elevations in core temperature during acute, passive heat exposure. In this study, we tested the hypothesis that loss of testosterone and related sex hormones through castration would improve the performance and heat tolerance of male mice during EHS exposure., Methods: Twenty-four male mice were randomly divided into 3 groups, untreated EHS mice (SHAM-EHS), castrated EHS mice (CAS+EHS) and naïve exercise controls (NAIVE). Exercise performance and physiological responses in the heat were monitored during EHS and early recovery. Two weeks later, blood and tissues were collected and analyzed for biomarkers of cardiac damage and testosterone., Results: Core temperature in CAS+EHS rose faster to 39.5°C in the early stages of the EHS trial (P<0.0001). However, both EHS groups ran similar distances, exhibited similar peak core temperatures and achieved similar exercise times in the heat, prior to symptom limitation (unconsciousness). CAS+EHS mice had ~10.5% lower body mass at the time of EHS, but this provided no apparent advantage in performance. There was no evidence of myocardial damage in any group, and testosterone levels were undetectable in CAS+EHS after gonadectomy., Conclusions: The results of these experiments exclude the hypothesis that reduced performance of male mice during EHS trials is due to the effects of male sex hormones or intact gonads. However, the results are consistent with a role of male sex hormones or intact gonads in suppressing the early and rapid rise in core temperature during the early stages of exercise in the heat., Competing Interests: The authors have declared that no competing interests exist.

New Findings: What is the topic of this review? The treatment of exertional heat stress, from initial field care through the return-to-activity decision. What advances does it highlight? Clinical assessment during field care using AVPU and vital signs to gauge recovery, approaches to field cooling and end of active cooling, and shared clinical decision making for return to activity recommendations., Abstract: Exertional heat stroke (EHS) is a potentially fatal condition characterized by central nervous system (CNS) dysfunction and body temperature often but not always >40°C that occurs in the context of physical work in warm or hot environments. In this paper, we review the continuum of care, from initial recognition and field care to transport and hospital care, and finally return-to-duty considerations. Morbidity and mortality can be greatly reduced if not eliminated with prompt recognition and aggressive cooling. If medical personnel are not present at point of collapse during or immediately following exercise, EHS should be the presumptive diagnosis until a formal diagnosis can be determined by qualified medical staff. EHS is a rare medical situation where initial treatment (cooling) takes precedence over transport to a medical facility, where advanced medical care may be required for severe EHS casualties. Recovery from EHS and return to activity is usually straightforward and unremarkable provided the casualty is rapidly cooled at time of collapse and adequate time is allowed for body healing. However, evidence-based data to guide return to activity following EHS are limited. Current research suggests that most individuals recover completely within a few weeks though some individuals may suffer prolonged sequalae and additional evaluation may be warranted, including heat tolerance testing (HTT). Several aspects of the care of the EHS casualty are based on best practices derived from personal experience and continued research is necessary to optimize evaluation and management., (© 2022 The Authors. Experimental Physiology © 2022 The Physiological Society.)

Heatstroke is a life-threatening event that affects people worldwide. Currently, there are no established tools to predict the outcomes of heatstroke. Although the Sequential Organ Failure Assessment (SOFA) score is a promising tool for judging the severity of critically ill patients. Therefore, in this study, we investigated whether the SOFA score could predict the outcome of patients hospitalized with severe heatstroke, including the classical and exertional types, by using data from a Japanese nationwide multicenter observational registry. We performed retrospective subanalyses of the Japanese Association for Acute Medicine heatstroke registry, 2019. Adults with a SOFA score ≥ 1 hospitalized for heatstroke were analyzed. We analyzed data for 225 patients. Univariate and multivariable analyses showed a significant difference in the SOFA score between non-survivors and survivors in classical and exertional heatstroke cases. The area under the receiver operating characteristic curve were 0.863 (classical) and 0.979 (exertional). The sensitivity and specificity of SOFA scores were 50.0% and 97.5% (classical), 66.7% and 97.5% (exertional), respectively, at a cutoff of 12.5, and 35.0% and 98.8% (classical), 33.3% and 100.0% (exertional), respectively, at a cutoff of 13.5. This study revealed that the SOFA score may predict mortality in patients with heatstroke and might be useful for assessing prognosis., (© 2022. The Author(s).)

Abstract: Background: No predictive models are currently available to predict poor prognosis in patients with severe heatstroke. We aimed to establish a predictive model to help clinicians identify the risk of death and customize individualized treatment. Methods: The medical records and data of 115 patients with severe heatstroke hospitalized in the intensive care unit of Changzhou No. 2 People's Hospital between June 2013 and September 2019 were retrospectively analyzed for modeling. Furthermore, data of 84 patients with severe heatstroke treated at Jintan No. 1 People's Hospital from June 2013 to 2021 were retrospectively analyzed for external verification of the model. We analyzed the hematological parameters of the patients recorded within 24 h of admission, which included routine blood tests, liver function, renal function, coagulation routine, and myocardial enzyme levels. Risk factors related to death in patients with severe heatstroke were screened using Least Absolute Shrinkage and Selection Operator regression. The independent variable risk ratio for death was investigated using the Cox univariate and multivariate regression analyses. The nomogram was subsequently used to establish a suitable prediction model. A receiver operating characteristic curve was drawn to evaluate the predictive power of the prediction model and the Acute Physiology and Chronic Health Evaluation (APACHE II) score. In addition, decision curve analysis was established to assess the clinical net benefit. The advantages and disadvantages of both models were evaluated using the integrated discrimination improvement and Net Reclassification Index. A calibration curve was constructed to assess predictive power and actual conditions. The external data sets were used to verify the predictive accuracy of the model. Results: All independent variables screened by Least Absolute Shrinkage and Selection Operator regression were independent risk factors for death in patients with severe heatstroke, which included neutrophil/lymphocyte ratio, platelet (PLT), troponin I, creatine kinase myocardial band, lactate dehydrogenase, human serum albumin, D-dimer, and APACHE-II scores. On days 10 and 30, the integrated discrimination improvement of the prediction model established was 0.311 and 0.364 times higher than that of the APACHE-II score, respectively; and the continuous Net Reclassification Index was 0.568 and 0.482 times higher than that of APACHE-II, respectively. Furthermore, we established that the area under the curve (AUC) of the prediction model was 0.905 and 0.918 on days 10 and 30, respectively. Decision curve analysis revealed that the AUC of this model was 7.67% and 10.67% on days 10 and 30, respectively. The calibration curve showed that the predicted conditions suitably fit the actual requirements. External data verification showed that the AUC on day 10 indicated by the prediction model was 0.908 (95% confidence interval, 82.2-99.4), and the AUC on day 30 was 0.930 (95% confidence interval, 0.860-0.999). Conclusion: The survival rate of patients with severe heatstroke within 24 h of admission on days 10 and 30 can be effectively predicted using a simple nomogram; additionally, this nomogram can be used to evaluate risks and make appropriate decisions in clinical settings., Competing Interests: The authors report no conflicts of interest., (Copyright © 2022 by the Shock Society.)

A 14-year-old female high school cross- country runner (height = 154 cm, mass = 48.1 kg) with no history of exertional heat stroke (EHS) collapsed at the end of a race. An athletic trainer assessed the patient, who presented with difficulty breathing and then other signs of EHS (eg, confusion and agitation). The patient was taken to the medical area and draped with a towel, and a rectal temperature (Tre) of 106.9°F (41.6°C) was obtained. The emergency action plan was activated, and emergency medical services was called. The patient was submerged in a cold-water immersion tub until emergency medical services arrived (∼15 minutes; Tre = 100.1°F; cooling rate: 0.41°F.min-1[0.25°C.min-1]). At the hospital, the patient received intravenous fluids, and urine and blood tests were normal. She was not admitted and returned to running without sequelae. Following best practices, secondary school athletic trainers can prevent deaths from EHS by properly recognizing the condition and providing rapid cooling before transport., (© by the National Athletic Trainers' Association, Inc.)

Objectives: To adapt key components of exertional heat stroke (EHS) prehospital management proposed by the Intenational Olympic Committee Adverse Weather Impact Expert Working Group for the Olympic Games Tokyo 2020 so that it is applicable for the Paralympic athletes., Methods: An expert working group representing members with research, clinical and lived sports experience from a Para sports perspective reviewed and revised the IOC consensus document of current best practice regarding the prehospital management of EHS., Results: Similar to Olympic competitions, Paralympic competitions are also scheduled under high environmental heat stress; thus, policies and procedures for EHS prehospital management should also be established and followed. For Olympic athletes, the basic principles of EHS prehospital care are: early recognition, early diagnosis, rapid, on-site cooling and advanced clinical care. Although these principles also apply for Paralympic athletes, slight differences related to athlete physiology (eg, autonomic dysfunction) and mechanisms for hands-on management (eg, transferring the collapsed athlete or techniques for whole-body cooling) may require adaptation for care of the Paralympic athlete., Conclusions: Prehospital management of EHS in the Paralympic setting employs the same procedures as for Olympic athletes with some important alterations., Competing Interests: Competing interests: WD reports grants from IOC Research Centers Grant, other from IPC Travel Support, grants from World Rugby, grants from AXA, grants from Ossur, outside the submitted work., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Heat stroke is a multiple organ dysfunction syndrome of poorly understood pathogenesis. Exertional heat stroke with acute liver failure is a rarely reported condition. Liver transplant has been recommended as treatment in cases of severe liver dysfunction; however, there are only 5 described cases of long-term survival after this procedure in patients with heat stroke. Here, we present 2 cases of young athletes who developed heat stroke. Both patients developed acute liver failure and were listed for liver transplant. Liver function tests of one patient improved, and he was discharged on postoperative day 13. The other patient showed no signs of improvement and liver biopsy showed massive necrosis. The patient underwent combined kidney-liver transplant and was discharged on postoperative day 17. After a follow-up of longer than 6 years, both patients are doing well with normal liver function and no neurologic sequelae. We also reviewed all published cases of hepatic failure associated with heat stroke and found 9 published cases of liver transplant for heat stroke in the English literature. Conservative management appears to be justified in heat stroke-associated liver failure, even in the presence of accepted criteria for emergency liver transplant. If the liver does not show signs of recovery and hepatic decompensation progresses, liver transplant should be performed.

Objective: Exertional heat stroke (EHS), characterised by a high core body temperature (Tcr) and central nervous system (CNS) dysfunction, is a concern for athletes, workers and military personnel who must train and perform in hot environments. The objective of this study was to determine whether algorithms that estimate Tcr from heart rate and gait instability from a trunk-worn sensor system can forward predict EHS onset., Methods: Heart rate and three-axis accelerometry data were collected from chest-worn sensors from 1806 US military personnel participating in timed 4/5-mile runs, and loaded marches of 7 and 12 miles; in total, 3422 high EHS-risk training datasets were available for analysis. Six soldiers were diagnosed with heat stroke and all had rectal temperatures of >41°C when first measured and were exhibiting CNS dysfunction. Estimated core temperature (ECTemp) was computed from sequential measures of heart rate. Gait instability was computed from three-axis accelerometry using features of pattern dispersion and autocorrelation., Results: The six soldiers who experienced heat stroke were among the hottest compared with the other soldiers in the respective training events with ECTemps ranging from 39.2°C to 40.8°C. Combining ECTemp and gait instability measures successfully identified all six EHS casualties at least 3.5 min in advance of collapse while falsely identifying 6.1% (209 total false positives) examples where exertional heat illness symptoms were neither observed nor reported. No false-negative cases were noted., Conclusion: The combination of two algorithms that estimate Tcr and ataxic gate appears promising for real-time alerting of impending EHS., Competing Interests: Competing interests: MBul is the listed inventor on a patent for estimating core body temperature from heart rate, also known as estimated core temperature (ECTemp). Ownership of the ECTemp patent is held by the US Department of the Army. MBul, RF, JS, BT and JRW and LW are the listed inventors on a patent application, 'System and Method to Predict Exertional Heat Stroke from Torso-Worn Sensor'. This patent is jointly owned by the US Department of the Army and Massachusetts Institute of Technology, Lincoln Laboratory. As part of the Department of Defense employee incentive programmes, MBul, RF and JS are entitled to receive a portion of royalty payments for any licensing of the algorithms., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

In the past two decades, record-breaking heatwaves have caused an increasing number of heat-related deaths, including heatstroke, globally. Heatstroke is a heat illness characterized by the rapid rise of core body temperature above 40 °C and central nervous system dysfunction. It is categorized as classic when it results from passive exposure to extreme environmental heat and as exertional when it develops during strenuous exercise. Classic heatstroke occurs in epidemic form and contributes to 9-37% of heat-related fatalities during heatwaves. Exertional heatstroke sporadically affects predominantly young and healthy individuals. Under intensive care, mortality reaches 26.5% and 63.2% in exertional and classic heatstroke, respectively. Pathological studies disclose endothelial cell injury, inflammation, widespread thrombosis and bleeding in most organs. Survivors of heatstroke may experience long-term neurological and cardiovascular complications with a persistent risk of death. No specific therapy other than rapid cooling is available. Physiological and morphological factors contribute to the susceptibility to heatstroke. Future research should identify genetic factors that further describe individual heat illness risk and form the basis of precision-based public health response. Prioritizing research towards fundamental mechanism and diagnostic biomarker discovery is crucial for the design of specific management approaches., (© 2022. Springer Nature Limited.)

Background: Exertional heat stroke (EHS) is a life-threatening illness that can lead to multiple organ damage in the early stage., Objective: This study aimed to investigate the relationship between 24-hour indicators and mortality in patients with EHS., Methods: The records of EHS patients hospitalized were collected and divided into the death group and the survival group. We then analyzed the demographic characteristics and APACHE II scores and laboratory results of the participants in the blood within the first 24 h after hospitalization, and assessed whether these candidate indicators differed between the death group and the survival group. Cox regression analysis of the survival data was performed to explore the relationship between early indicators and prognosis., Results: The levels of plasma PT, APTT, TT, and INR were significantly higher in the death group than in the survival group. The blood PLT count and the levels of PTA and Fb were significantly lower in the death group than in the survival group, while the levels of BU, SCr, ALT, AST, TBil, and DBil were significantly higher in the death group than in the survival group. Furthermore, the levels of Mb, LDH, TNI, and NT-proBNP were significantly higher in the death group than in the survival group, while there was no significant difference in CK levels between the two groups., Conclusion: Patients with EHS often had multiple organ injuries in the early stage (within 24 h), while those cases in the death group were more severe., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Objectives: This document aimed to summarise the key components of exertional heat stroke (EHS) prehospital management., Methods: Members of the International Olympic Committee Adverse Weather Impact Expert Working Group for the Olympic Games Tokyo 2020 summarised the current best practice regarding the EHS prehospital management., Results: Sports competitions that are scheduled under high environmental heat stress or those that include events with high metabolic demands should implement and adopt policy and procedures for EHS prehospital management. The basic principles of EHS prehospital care are: early recognition, early diagnosis, rapid, on-site cooling and advanced clinical care. In order to achieve these principles, medical organisers must establish an area called the heat deck within or adjacent to the main medical tent that is optimised for EHS diagnosis, treatment and monitoring. Once admitted to the heat deck, the rectal temperature of the athlete with suspected EHS is assessed to confirm an elevated core body temperature. After EHS is diagnosed, the athlete must be cooled on-site until the rectal temperature is below 39°C. While cooling the athlete, medical providers are recommended to conduct a blood analysis to rule out exercise-associated hyponatraemia or hypoglycaemia, provided that this can be safely performed without interrupting cooling. The athlete is transported to advanced care for a full medical evaluation only after the treatment has been provided on-site., Conclusions: A coordination of care among all medical stakeholders at the sports venue, during transport, and at the hospital is warranted to ensure effective management is provided to the EHS athlete., Competing Interests: Competing interests: All authors are members of the International Olympic Committee Adverse Weather Impact expert working Group for the Olympic Games Tokyo 2020; not receiving honorarium., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Abstract: Exertional heat stroke (EHS) is a true medical emergency with potential for organ injury and death. This consensus statement emphasizes that optimal exertional heat illness management is promoted by a synchronized chain of survival that promotes rapid recognition and management, as well as communication between care teams. Health care providers should be confident in the definitions, etiologies, and nuances of exertional heat exhaustion, exertional heat injury, and EHS. Identifying the athlete with suspected EHS early in the course, stopping activity (body heat generation), and providing rapid total body cooling are essential for survival, and like any critical life-threatening situation (cardiac arrest, brain stroke, sepsis), time is tissue. Recovery from EHS is variable, and outcomes are likely related to the duration of severe hyperthermia. Most exertional heat illnesses can be prevented with the recognition and modification of well-described risk factors ideally addressed through leadership, policy, and on-site health care., (Copyright © 2021 by the American College of Sports Medicine.)

This study aims to develop and validate prediction models for the number of all heatstroke cases, and heatstrokes of hospital admission and death cases per city per 12 h, using multiple weather information and a population-based database for heatstroke patients in 16 Japanese cities (corresponding to around a 10,000,000 population size). In the testing dataset, mean absolute percentage error of generalized linear models with wet bulb globe temperature as the only predictor and the optimal models, respectively, are 43.0% and 14.8% for spikes in the number of all heatstroke cases, and 37.7% and 10.6% for spikes in the number of heatstrokes of hospital admission and death cases. The optimal models predict the spikes in the number of heatstrokes well by machine learning methods including non-linear multivariable predictors and/or under-sampling and bagging. Here, we develop prediction models whose predictive performances are high enough to be implemented in public health settings., (© 2021. The Author(s).)

Background and Importance: Heat stroke is a life-threatening condition affecting children worldwide. Rapid cooling remains the most important feature of emergency management. The accepted preferred method of evaporative cooling in the ED as listed by the reference text book endorsed by the Israeli Society of Pediatric Emergency Medicine (PEMI), is actively cooling the patient by spraying him with water and positioning fans to blow air across the body., Objective: This study aimed to assess Israeli health care workers (HCWs) medical professionals' knowledge and preparedness of treating heat stroke and recommend policy changes to ensure better treatment based on survey results., Design, Settings and Participants: A cross-sectional survey of all HCWs working in an ED that accepts children was conducted. An online questionnaire was utilized to assess heat stroke management practices and available resources in all Israeli pediatric emergency departments (PEDs)., Main Results: Data from 208 health care workers was analyzed. Only 30% of the participants reported ever treating a patient with exertional heat stroke. Two scenarios were presented to the participants: motor vehicle-related child hyperthermia (MVRCH) in an infant and an adolescent with exertional heat stroke. One hundred twenty-five (60%) and 83 (40%) participants, respectively, listed cool water with a fan as the primary mode of cooling, which is considered the appropriate preferred method of evaporative cooling in the PED. Certificated pediatric emergency medicine (PEM) physicians answered significantly more correctly regarding both scenarios' management (P < 0.001). Participants who were trained via simulation in the past, answered significantly more correctly regarding the exertional heat stroke scenario (P < 0.01), however no difference was found regarding the MVRCH case., Conclusions: The present study exposes weaknesses in HCW knowledge, PED resources, and published PED policies for appropriate management of children following heat stroke. Our finding emphasizes the importance of both certificated PEM physicians attendance and simulation performance for implementing proper management of patients with heat stroke. A policy change should be performed among the Israeli PED community, with respect to establishing and implementing guidelines for treatment of exertional heat stroke. A future study, following an interventional simulation program is planned to be performed.

Background: Heatstroke is becoming an increasingly serious threat to outdoor activities, especially, at the time of large events organized during summer, including the Olympic Games or various types of happenings in amusement parks like Disneyland or other popular venues. The risk of heatstroke is naturally affected by a high temperature, but it is also dependent on various other contextual factors such as the presence of shaded areas along traveling routes or the distribution of relief stations. The purpose of the study is to develop a method to reduce the heatstroke risk of pedestrians for large outdoor events by optimizing relief station placement, volume scheduling and route., Results: Our experiments conducted on the planned site of the Tokyo Olympics and simulated during the two weeks of the Olympics schedule indicate that planning routes and setting relief stations with our proposed optimization model could effectively reduce heatstroke risk. Besides, the results show that supply volume scheduling optimization can further reduce the risk of heatstroke. The route with the shortest length may not be the route with the least risk, relief station and physical environment need to be considered and the proposed method can balance these factors., Conclusions: This study proposed a novel emergency service problem that can be applied in large outdoor event scenarios with multiple walking flows. To solve the problem, an effective method is developed and evaluates the heatstroke risk in outdoor space by utilizing context-aware indicators which are determined by large and heterogeneous data including facilities, road networks and street view images. We propose a Mixed Integer Nonlinear Programming model for optimizing routes of pedestrians, determining the location of relief stations and the supply volume in each relief station. The proposed method can help organizers better prepare for the event and pedestrians participate in the event more safely.