The Heat and Health Index (HHI) helps identify communities where people are most likely to feel the effects of heat on their health, in order to build towards a healthier and more heat-resilient future for all. The (HHI) is a national tool that incorporates historical temperature, heat-related illness, and community characteristics data at the ZIP code or ZCTA level to identify areas most likely to experience negative health outcomes from heat and help communities prepare for heat in a changing climate. Each ZCTA has a single ranking for the overall HHI and rankings for individual components so that users can make informed decisions to prepare for and prevent the negative health impacts from heat in their communities. The HHI consists of 25 data indicators of heat and health vulnerability to help communities prepare for warming temperatures in a changing climate. These indicators are grouped into 4 modules.
Data in the HHI come from the Centers for Disease Control and Prevention (CDC), the National Emergency Medical Services Information System (NEMSIS), the United States Census Bureau, the Multi-Resolution Land Characteristics Consortium (MRLC), and the Environmental Protection Agency (EPA).