The goal of this clinical trial is to learn if infrastructure and equipment installed to cool homes reduce adverse health outcomes. The main questions it aims to answer are:

What is the impact of the intervention on indoor heat stress? What is the impact of the intervention on personal exposure to heat stress? What is the impact of the intervention on health outcomes, including heart rate, and heart rate variability, and sleep quality?

Participants will have cooling infrastructure and/or equipment installed in their home; have heat stress sensors installed inside and outside their home and wear personal heat stress monitors; allow some biological functions such as heat rate, heat rate variability, and sleep quality.

During the last two decades, nearly half a million people died each year from heat-related causes; climate change is expected to exacerbate the burden of adverse health outcomes. Heat stress has been associated with an increase in all-cause mortality, cardiovascular disease and mortality, chronic respiratory disease, lower respiratory infection, chronic kidney disease, diabetes, adverse pregnancy outcomes, and poor mental health. The investigators will to determine personal heat stress of low-income individuals who do not have access to air conditioning, evaluate the effectiveness, acceptability, feasibility, and scalability of building-level cooling strategies to reduce indoor heat stress among vulnerable individuals, and evaluate the impact of these interventions on heart rate. A disproportionate burden of heat-related death and disease is borne by low-income communities because they do not have access to cooling and suffer from comorbidities that exacerbate the adverse impacts of heat stress. South Asia faces the greatest current and predicted loss in disability-adjusted life years due to heat stress, and heat stress is particularly strong in informal settlements. As such, the investigators plan to conduct this study in informal settlements in Dhaka, Bangladesh. The overall hypothesis is that individuals who live in homes with corrugated iron roofs and walls are at elevated risk of heat stress and that it is possible to modify homes to prevent increases in heart rate associated with heat stress, ultimately reducing cardiovascular morbidity and mortality. The investigators will evaluate the impact of cooling infrastructure and/or equipment interventions on residents' heart rate (primary outcome), heart rate variability, sleep quality, self-reported thermal comfort, mental health, wellness, fatigue, and indoor thermal conditions (secondary outcomes).

Inclusion Criteria for the house:

• House is located in an informal settlement in an urban area in Bangladesh
• The house has a corrugated iron roof and corrugated iron walls
• The household plans to remain in the house from Feb-Nov

Exclusion Criteria for the house

• There is an inhabited structure about the house
• The landlord does not allow the proposed intervention

Inclusion Criteria for the participant:

• Lives in an eligible household

Exclusion Criteria for the participant

• Has access to air conditioning in their home or place of work
• Reports they are pregnant
• Has hypertension, as measured by study staff
• Has diabetes, as measured by study staff
• Self-reports cardiovascular disease / chronic cardiac condition
• Self-reports respiratory disease / chronic respiratory condition

Deidentified individual participant data will be stored in icddrb's data repository

The investigators expect the data to become available at least by 1 Jan 2030. The investigators have no plan for when the data will become unavailable.

Reasonable request