The long-term research goal is to identify viable passive housing adaptation technologies with proven health and environmental benefits to reduce the burden of heat stress in communities affected by heat in Africa. As a next step towards this goal, the project proposes to conduct a household-randomized controlled trial (RCT) in Nouna, Burkina Faso to: (i) establish the effect of the cool roof on the primary endpoint heart rate (as an indicator of physiological stress) and (ii) quantify the effects of the cool roof on a range of secondary endpoints, including indoor temperature, indoor humidity, cardiovascular morbidity and mortality, household energy consumption, and socioeconomic outcomes.