Beat the Heat Boston

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.