Beat the Heat Boston

NCT ID: NCT06982339

Last Updated: 2026-01-22

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 100 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-05-19
• Study Completion Date: 2026-10-15

Brief Summary

The goal of this stepped wedge trial is to assess the practical effects of air conditioners on hot weather impacts among older adults. The main questions it aims to answer are:

How does the presence of an air conditioning unit affect heat stress, heat strain, mental health, and healthcare utilization among older adults who did not previously have access to air conditioning?

How, and in what conditioners, do older adults use air conditioning once it is installed in their home?

Researchers will compare participants in arms with (A) and without (B) air conditioning units in the first summer season; this will allow them to assess the effect of air conditioners. In the second summer season, both arms will have air conditioning units, but those in the year two distribution arm (B) will receive an electricity subsidy, while those in the year one AC distribution arm (A) will not, allowing researchers to assess the effect of an electricity subsidy.

Participants will be randomized to receive an air conditioner and financial support for electricity costs in either the first summer season or the second summer season of the study.

• Heat stress, heat strain, mental health, and healthcare utilization will be assessed via participant survey.
• Air conditioner utilization will be assessed via continuous load monitoring devices.
• Indoor air temperature will be assessed via continuous data loggers.

Detailed Description

This community-based, randomized stepped wedge trial investigates whether the provision of educational resources and air conditioning (AC) improves thermal comfort and health outcomes among older adults with chronic disease and material hardships. The study will enroll 100 participants residing in at risk neighborhoods. Eligibility criteria include adults aged 55-95 who speak English or Spanish, lack access to home cooling systems, and have at least one qualifying chronic health condition or a history of recent hospitalization (see Eligibility section) .

Participants will be randomly assigned (1:1) to receive window AC units and an electricity cost subsidy either in Year 1 or Year 2. All participants in both arms will receive a baseline intervention including heat health educational materials and cooling kits. Data collection will occur over two warm seasons (April-September) and involve pre- and post-intervention assessments using structured surveys, real-time environmental monitoring, and AC usage tracking.

Surveys administered at enrollment and in late summer each year will capture a broad range of covariates including sociodemographic data, housing conditions, health service utilization, self-reported symptoms, and adaptive behaviors. Heat stress, heat strain, mental health, and healthcare utilization outcomes will be assessed via surveys that include previously validated survey instruments. Specific emphasis will be placed on measures of energy insecurity, such as utility shutoff notices, receipt of energy assistance, and trade-offs between essential expenses. Environmental sensors will log indoor temperature, humidity, and pollutant data throughout the study period.

The primary outcome is self-reported health status as measured by a modified ESQ-IV, supplemented by secondary metrics including ASHRAE thermal comfort scores, POMS, emergency department presentations, and hospitalizations. Statistical analysis will employ two-sample t-tests to detect treatment effects, with a minimum detectable effect size of 5.66 assuming a standard deviation of 10 and balanced sample sizes.

This study aims to empirically quantify the health benefits of cooling interventions in high-risk older adults and inform scalable public health strategies that address the intersecting challenges of urban heat, chronic disease management, and housing-related inequities.

Conditions

Hot Weather; Adverse Effect; Heat Effect; Heat Stress; Heat Stroke, Heat Exhaustion; Heat Exposure; Heat Strain

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: NONE

Study Groups

Early Air Conditioning

Year 1: Participants receive a window AC unit and a financial subsidy for electricity.

Year 2: Participants continue to have their AC unit, but do not receive a financial subsidy for electricity.

Group Type: EXPERIMENTAL

Air Conditioner

Intervention Type: OTHER

Air conditioners will be window-mounted units powered by 110v AC.

Electricity subsidy

Intervention Type: OTHER

Electricity subsidies will consist of a single block subsidy of USD 100, intended to provide support for the electricity costs associated with operating an air conditioning unit.

Delayed Air Conditioning

Year 1: No intervention. Year 2: Participants receive an AC unit along with a financial subsidy for electricity.

Group Type: NO_INTERVENTION

No interventions assigned to this group

Interventions

Air Conditioner

Air conditioners will be window-mounted units powered by 110v AC.

Intervention Type: OTHER

Electricity subsidy

Electricity subsidies will consist of a single block subsidy of USD 100, intended to provide support for the electricity costs associated with operating an air conditioning unit.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• reside in Roxbury, Dorchester, East Boston or Mattapan MA
• age 55-95 years old
• speak English or Spanish
• do not have air conditioning in the home
• living with at least one of the following conditions: chronic CVD (hypertension, hyperlipidemia, diabetes, history of stroke or myocardial infarction, atrial fibrillation, or heart failure), chronic pulmonary disease (asthma, COPD/emphysema, interstitial lung disease), chronic neurologic disease (stroke, Parkinson's disease, or other chronic neurologic conditions), chronic mental health conditions (including anxiety disorder, major depression, bipolar disorder), and/or history of hospitalization (defined as spending at least one night in the hospital) for any reason within the past three years.

Exclusion Criteria

• Lack a location in their home suitable for installation of the AC unit provided during the research study.

• Minimum Eligible Age: 55 Years
• Maximum Eligible Age: 95 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Fogarty International Center of the National Institute of Health

NIH

Sponsor Role: collaborator

Harvard School of Public Health (HSPH)

OTHER

Sponsor Role: lead

Responsible Party

Gary Adamkiewicz

Associate Professor of Environmental Health and Exposure Disparities

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Gary Adamkiewicz Associate Professor of Environmental Health and Exposure Disp., PhD, MPH, MS

Role: PRINCIPAL_INVESTIGATOR

Harvard School of Public Health (HSPH)

Locations

Harvard TH Chan School of Public Health

Boston, Massachusetts, United States

Site Status: RECRUITING

Countries

United States

Central Contacts

Caleb Dresser Assistant Professor in Environmental Health, MD MPH

Role: CONTACT

beattheheatboston@gmail.com

(617) 446-3248

Facility Contacts

Caleb J Dresser, MD MPH

Role: primary

cdresser@hsph.harvard.edu

6174950000

Other Identifiers

1P20TW013028-01

Identifier Type: NIH

Identifier Source: secondary_id

View Link

IRB25-0366

Identifier Type: -

Identifier Source: org_study_id