Assessing the Effect of Cool Roofs on Health Using Smartwatches in Colima, Mexico

Ambient air temperatures in Mexico have broken record highs in 2024. Solutions are needed to build heat resilience in communities and adapt to increasing heat from climate change. Sunlight-reflecting cool roof coatings may passively reduce indoor temperatures and energy use to protect home occupants from extreme heat. Occupants living in poor housing conditions in the northern zone of Mexico are susceptible to increased heat exposure. Heat exposure can instigate and worsen numerous physical, mental and social health conditions. The worst adverse health effects are experienced in communities that are least able to adapt to heat exposure. By reducing indoor temperatures, cool roof use may promote heart health, sleep and physical activity in household occupants. The long-term research goal of the investigators is to identify viable passive housing adaptation technologies with proven health benefits to reduce the burden of heat stress in communities affected by heat in Mexico. To meet this goal, the investigators will conduct a randomized controlled trial to establish the effects of cool roof use on heart rate, sleep and physical activity in Colima, Mexico.

NCT Number	NCT06831006
Lead Sponsor	University of Auckland, New Zealand Collaborators: Heidelberg University, London School of Hygiene and Tropical Medicine, Rutgers University, Labfront, Wellcome Trust, EPS, Universidad de Colima
Conditions	Heart Rate, All-day Steps, Distance Walked, Active Minutes, Moderate-intensity Activity Minutes, Vigorous-intensity Activity Duration, Sleep Quantity, Time in Sleep Stages +2 more
Enrollment	800 participants
Start Date	2026-04-01
Primary Completion	2027-09-01 (estimated)
Study Completion	2027-09-01 (estimated)
Updated on ClinicalTrials.gov	2026-03-11