Randomized Crossover Study on the Effects of Daytime, Nighttime, and Combined Heat Exposure on Heart, Lung, Brain, and Metabolic Health in Healthy Young Adults Aged 18 to 30

What this Trial Is About

Researchers are investigating the short-term effects of high-temperature exposure during both day and night on various bodily functions including cardiovascular, respiratory, neurocognitive, and metabolic health. This randomized controlled crossover trial involves about 50 healthy young adults in Hefei, China, aiming to understand how heat affects these systems and to explore the biological mechanisms behind these effects. Participants will experience three different heat exposure conditions in random order nighttime heat at 306C, daytime heat at 326C, and combined day-night heat exposure. Each exposure lasts about 8 hours during typical sleep or work periods, with breaks of at least three days between sessions to avoid carryover effects. Control exposures at a neutral temperature of 266C will also occur for comparison. During exposures, participants will rest to limit physical activity. Throughout the study, health assessments will be made before, during, and after each exposure. These include heart rate monitoring with a smart band for 24 hours, blood pressure, lung function tests, cognitive and psychological evaluations, and collection of blood and urine samples to measure inflammation, oxidative stress, and kidney function markers. Mood and stress levels will also be assessed to provide a comprehensive picture of the acute physiological and psychological responses to heat exposure.

The Effects of Daytime, Nighttime, and Combined Heat Exposure on Human Health