Assessing the Effect of Cool Roofs on Health Using Smartwatches in Ouagadougou, Burkina Faso

A Cluster Randomized Controlled Trial (cRCT) Evaluating the Effects of Cool Roofs on Health Outcomes Using Smartwatches in Ouagadougou, Burkina Faso

Ambient air temperatures in Africa, 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- for example in informal settlements, slums, and low-socioeconomic households - 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 application may improve heart health, sleep and physical activity in household occupants.

The long-term research goal is to identify viable passive housing adaptation technologies with proven health benefits to reduce the burden of heat stress in communities affected by heat. To meet this goal, the investigators will use smartwatches to measure the effects cool roof application on heart health, sleep and physical activity in Ouagadougou, Burkina Faso.

Increasing heat exposure from climate change is causing and exacerbating heat-related illnesses in millions worldwide - particularly in low resource settings. June 2024 was the 13th consecutive hottest month on record globally - shattering previous records. Heat exposure can instigate and worsen numerous health conditions. Adaptation is essential for protecting people from increasing heat exposure. The built environment, especially homes, are ideal for deploying interventions to reduce heat exposure and accelerate adaptation efforts. However, evidence is currently lacking on a global scale - generated through empirical studies - guiding the uptake of interventions to reduce indoor heat stress in low resource settings.

Sunlight-reflecting cool roof coatings passively reduce indoor temperatures and lower energy use, offering protection to home occupants from extreme heat. Continuous monitoring of health and wellbeing using smartwatches can provide insight into important parameters such as heart rate, sleep and physical activity - which are all affected by heat. Using smartwatches, the investigators will also continuously measure health and wellbeing outcomes during the day and night. The investigators will conduct a study to investigate the effects of cool-roof use on heart rate, sleep and physical activity in Ouagadougou, Burkina Faso (sub-Saharan Africa, where people experience a triple burden from heat exposure, chronic health issues and vulnerable housing conditions (slums, informal settlements and low socioeconomic housing).

This trial will quantify whether cool roofs are an effective passive home cooling intervention with beneficial health effects for vulnerable populations in Burkina Faso. Findings will inform global policy responses on scaling cool roof implementation to protect people from increasing heat exposure driven by climate change.

Inclusion Criteria:

• • Permanent household resident

Exclusion Criteria:

• • Roof damage, inaccessible or instability of roof adversely affecting cool roof coating application.

  • Participant unable to provide written/verbal informed consent. Participants will be excluded if they are not willing or able to wear a smartwatch.
  • One participant per household.