The Heat and Health Index: A Tool to Help Communities Prepare for and Effectively Respond to Heat

Heat is the deadliest weather-related hazard and is responsible for approximately 1,220 deaths each year on average. 2023 was the hottest year on record in the U.S. and globally, and the frequency and intensity of extreme heat events will continue to increase with climate change. Decisionmakers need tools and information to help prepare for heat and prevent heat-related illness and deaths. This presentation will discuss the new Heat and Health Index (HHI) developed at the Centers for Disease Control and Prevention’s Agency for Toxic Substances and Disease Registry in partnership with the Department of Health and Human Services’ Office of Climate Change and Health Equity. The HHI is the first nationwide tool to combine ZIP code-level data on historical heat exposure and heat-related illness, pre-existing health conditions, sociodemographic factors, and natural and built environment characteristics to measure vulnerability to heat. By delivering a percentile ranking for each ZIP code, the HHI helps public health officials, city planners, policymakers, and community members pinpoint areas most likely to experience negative health outcomes from heat across the country. It also details local factors that may be driving this risk, which can help inform interventions to protect public health and build a more heat-resilient future. Specifically, the HHI can be used to 1) identify and prioritize areas that may require special attention during heat events to reduce heat-related illness, 2) educate and inform the public about heat risk in their community, and 3) analyze the unique, local factors driving heat-related illness to inform policy and decision making.