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Objectives The elderly population is at an increasingly significant health risk to heat-related illnesses and mortality when compared with younger people in the same conditions. This is due to an increased frequency and severity of heatwaves, attributed to climate change, and reduced ability of elderly individuals to dissipate excess heat. Consequently, most excess deaths and emergency visits during heatwaves occur in people aged more than 65 years. The aim of this investigation was to assess the physiological and perceptual responses of elderly people during exercise sessions equating to activities of daily living in UK summer climatic conditions. Study design Mixed-method, randomised research design. Methods Twenty-eight participants (17 males, 10 females and 1 transgender female) were randomly assigned into three experimental groups; 15°C, 25°C or 35°C, with 50% relative humidity. Participants completed one preliminary and three experimental trials within their assigned environment. The data from the preliminary incremental recumbent cycling test was used to calculate participant's individual exercise intensities equating to 2, 4 and 6 metabolic equivalents (METs) for the subsequent trials. During experimental trials, participants completed 30-min seated rest and 30-min cycling. Results No change was observed in thermal comfort ([TC] just uncomfortable in both trials), and only modest changes in ratings of perceived exertion (14 ± 2 vs 15 ± 2) at 6 METs in 25°C compared with those in 35°C were observed. In contrast, thermal strain markers did significantly increase (P < 0.05) across the same conditions, including change in rectal temperature (ΔTre) during exercise (0.27 ± 0.17°C vs 0.64 ± 0.18°C) and peak skin temperature ([Tskin] 32.94 ± 1.15°C vs 36.11 ± 0.44°C). Conclusion When completing exercise that equates to activities of daily living, elderly people could have a decreased perceptual awareness of the environment even though physiological markers of thermal strain are elevated. Consequently, the elderly could be less likely to implement behavioural thermoregulation interventions (i.e. seek shade and/or remove excess layers) due to a decreased awareness of an increasingly thermally challenging environment. [ABSTRACT FROM AUTHOR]

Objectives: The elderly are the most at-risk population for heat-related illness and mortality during the periods of hot weather. However, evidence-based elderly-specific cooling strategies to prevent heat-illness are limited. The aim of this investigation was to quantify the elderly's physiological and perceptual responses to cooling through cold water ingestion (COLD) or an L-menthol mouth rinse (MENT) during simulated activities of daily living in UK summer climatic conditions., Study Design: Randomised, controlled repeated measures research design., Methods: A total of ten participants (men n = 7, women n = 3: age; 69 ± 3 yrs, height; 168 ± 10 cm, body mass; 68.88 ± 13.72 kg) completed one preliminary and three experimental trials; control (CON), COLD and MENT. Experimental trials consisted of 40 min rest followed by 30 min of cycling exercise at 6 metabolic equivalents and a 6-min walk test (6MWT), within a 35 °C, 50% relative humidity environment. Experimental interventions (every 10 min); cold water (4 °C) ingestion (total of 1.5L) or menthol (5 ml mouth swill for 5 s, menthol concentration of 0.01%)., Results: Peak rectal temperature (T re ) was significantly (P < 0.05) lower in COLD compared with CON (-0.34 ± 0.16 °C) and MENT (-0.36 ± 0.20 °C). End exercise heart rate (HR) decreased in COLD compared with CON (-7 ± 9 b min -1 ) and MENT (-6 ± 7 b min -1 ). There was no difference in end exercise thermal sensation (TS) (CON; 6.1 ± 0.4, COLD; 6.0 ± 0.4, MENT; 6.4 ± 0.6) or thermal comfort (TC) (CON; 4 ± 1, COLD; 4 ± 1, MENT; 4 ± 1) between trials. The participants walked significantly further during the COLD 6MWT compared with CON (40 m ± 40 m) and MENT (40 m ± 30 m). There was reduced physiological strain in the COLD 6MWT compared with CON (T re ; -0.21 ± 0.24 °C, HR; -7 ± 8 b min -1 ) and MENT (T re ; -0.23 ± 0.24 °C, HR; -4 ± 7 b min -1 )., Conclusion: The elderly have reduced physiological strain (T re and HR) during activities of daily living and a 6MWT in hot UK climatic conditions, when they drink cold water. Furthermore, the elderly's perception (TS and TC) of the hot environment did not differ from CON at the end of exercise with COLD or MENT interventions. Menthol provided neither perceptual benefit to exercise in the heat nor functional gain. The TS data indicate that elderly may be at increased risk of heat illness, due to not feeling hot and uncomfortable enough to implement physiological strain reducing strategies such as cold-water ingestion., (Copyright © 2021 The Royal Society for Public Health. All rights reserved.)