Assessing the Effects of Cool Roofs on Indoor Environments and Health in Hermosillo, Mexico

Summary

Ambient air temperatures in Mexico have broken record highs in 2024 with Hermosillo reaching the highest maximum temperature recorded in Mexico at 51.9 C. 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 can promote physical, mental and social wellbeing 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 northern zone of Mexico. To meet this goal, the investigators will conduct a cluster-randomized controlled trial to establish the effects of cool roof use on health, indoor environment and economic outcomes in Hermosillo, Mexico.

Conditions

• Resting Heart Rate
• Blood Glucose Control
• Depression
• Heat-related Symptoms
• Physician Diagnosed Heat-related Illnesses
• Food Insecurity
• Diet Quality
• Health-related Quality of Life
• Indoor Thermal Comfort
• Coping Ability
• Life Satisfaction
• Healthcare Provider Utilization
• Hospitalization
• Systolic Blood Pressure
• Diastolic Blood Pressure
• Inner Ear Canal Temperature
• Dehydration
• Sleep Quality
• Cognition
• Productivity
• Aggression
• Indoor Air Temperature
• Indoor Relative Humidity
• Indoor Heat Index
• Household Energy Expenditure

Interventions

OTHER

Cool roof

Cool roofs are a heat-reflecting material that can be applied to existing household roofing in the form of a liquid-applied membrane. Cool roofs work by increasing solar reflectance (the ability to reflect the visible wavelengths of sunlight, reducing heat transfer to the surface) and thermal emittance (the ability to radiate absorbed solar energy) thereby reducing the amount of heat transferred into the home.

Sponsors & Collaborators

• Heidelberg University

  collaborator OTHER

• Rutgers University

  collaborator OTHER

• Boston University

  collaborator OTHER

• Secretaría de Educación Pública, México

  collaborator OTHER_GOV

• CogniFit Limited

  collaborator UNKNOWN

• EPS

  collaborator UNKNOWN

• London School of Hygiene and Tropical Medicine

  collaborator OTHER

• Aditi Bunker

  lead OTHER

Principal Investigators

• Collin Tukuitonga, Sir. Dr. · University of Auckland, New Zealand

Study Design

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2025-03-01

Primary Completion

2026-05-01

Completion

2026-05-01

Countries

• Mexico

Study Locations