Assessing the Safety of a 26C Indoor Temperature Limit for Older Adults Considering Clothing and Daily Activity Effects

What this Trial Is About

Researchers are examining how well the current recommended indoor temperature limit of 266C protects older adults aged 65 to 85 years from heat stress, especially considering the effects of clothing and daily activities. Older adults may not feel heat as strongly as younger people, which can lead to wearing too much clothing or not adjusting activity levels, potentially increasing body temperature and cardiovascular strain. This study aims to understand if the temperature limit needs adjustment to better safeguard health during hot weather. Participants will be exposed on separate occasions for 8 hours to an indoor environment maintained at 266C with 45% relative humidity, simulating comfortable conditions. Four scenarios will be tested seated rest wearing light clothing t-shirt, shorts, socks, light exercise every hour wearing light clothing, seated rest wearing light clothing plus an added layer sweatshirt and sweatpants, and light exercise every hour wearing light clothing with the added layer. These conditions represent common daily activities and clothing habits among older adults. During each 8-hour exposure, researchers will measure core body temperature and cardiovascular strain. Additional assessments include mood, hydration, exertion, cognitive function, blood pressure, heart rate variability, balance, thermal comfort, and fluid loss. These measurements will help determine physiological responses to heat under different clothing and activity conditions. The study will also monitor symptoms and overall well-being to evaluate safety and comfort during exposure.

Suitability of the 26 °C Indoor Temperature Upper Limit for Older Adults: Impacts of Clothing and Daily Activity