How daytime, nighttime, and combined heat exposure affect healthy young adults' bodies
Randomized Controlled Crossover Trial on the Effects of Daytime, Nighttime, and Combined Heat Exposure on Human Health
This test will see if short high-temperature exposures during the day, at night, or both change heart, lung, metabolic, and mental measures in healthy adults aged 18–30.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 35 (estimated) |
| Ages | 18 Years to 30 Years |
| Sex | All |
| Sponsor | Anhui Medical University Academic / other |
| Locations | 1 site (Hefei, Anhui) |
| Trial ID | NCT07501923 on ClinicalTrials.gov |
What this trial studies
This randomized, controlled crossover human exposure trial in Hefei will enroll about 50 healthy young adults to measure acute physiological and psychological responses to heat. Participants undergo three exposure conditions—nighttime heat (30°C, 23:00–07:00), daytime heat (32°C, 09:00–17:00), and combined day–night exposures—each compared with a thermoneutral 26°C condition with at least a three-day washout between sessions. The study will collect cardiovascular, respiratory, neurocognitive, and metabolic outcomes and explore underlying biological mechanisms. Randomized crossover sequencing ensures within-subject comparisons of the different temperature conditions.
Who should consider this trial
Good fit: Healthy non-smoking adults aged 18–30 without chronic cardiovascular, respiratory, endocrine, neurological, or psychiatric disorders, not pregnant or lactating, and not taking medications that affect cognition or cardiorespiratory function are ideal candidates.
Not a fit: People with chronic heart or lung disease, diabetes, older adults, pregnant or breastfeeding women, or those on relevant medications are unlikely to gain direct benefit and are excluded for safety.
Why it matters
Potential benefit: If successful, the findings could help shape public health guidance and recommendations for sleep and workplace environments to reduce heat-related cardiovascular, respiratory, and metabolic risks.
How similar studies have performed: Previous laboratory and epidemiological work has documented heat-related changes in cardiovascular and metabolic function, but randomized crossover comparisons of daytime, nighttime, and combined exposures are limited, so this design is partly novel.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * Age 18-30; * In good health, with no history of cardiovascular disease, respiratory disease, diabetes, endocrine disorders, neurological or psychiatric conditions; * No smoking or alcohol addiction, no history of substance abuse; * No prior history of particular sensitivity to high-temperature environments. Exclusion Criteria: * Individuals who have experienced fever, colds, infectious diseases, or significant physical trauma within two weeks prior to the high-temperature test; * Individuals currently using medications that may affect psychological, cognitive, cardiovascular, or respiratory functions; * Pregnant women and lactating females; * Participants shall not be scheduled to participate during menstruation; * Individuals with a history of fainting or severe discomfort caused by high temperatures.
Where this trial is running
Hefei, Anhui
- Anhui Medical University — Hefei, Anhui, China (Recruiting)
Study contacts
- Study coordinator: Jian Jian Cheng
- Email: jiancheng@ahmu.edu.cn
- Phone: +86 183 5603 7837
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.