Rapidly Developing a Community- and Evidence-Based Heat Action Plan

Extreme heat contributes to 8000-12 000 excess U.S. deaths per year. Partly due to increasing summer temperatures and a renewed focus on environmental justice, local governments started new initiatives to manage and adapt to extreme heat. For example, Miami -Dade County, Florida, United States, appointed Jane Gilbert as the world's first Chief Heat Officer. This manuscript summarizes Miami -Dade County's preliminary efforts to build local evidence, engage the community, and rapidly respond to extreme heat. The manuscript's goal is to expedite the translation of existing tools into mainstream extreme heat, health, and equity planning. The study generated local evidence to identify the places and periods of time with elevated heat -related illness using a statistical vulnerability and time series analysis, respectively. The places with the highest severe heat -related illness rates had hotter land surface temperatures and/or higher proportions of people who were outdoor workers, Indigenous, living in poverty or mobile homes, and households with children. "Everyday" summer conditions instead of rare heatwaves increase the risk of a heat -related death. The Chief Heat Officer convened workshops that engaged 298 unique community members on six cross-sectoral heat topics. Key recommendations included increasing multisectoral heat monitoring and risk communication, building more affordable housing, preserving and expanding greenspace, and creating heat resilience hubs. The activities culminated in a Heat Action Plan, which was completed in less than two years from the receipt of project funding. SIGNIFICANCE STATEMENT: Extreme heat is a contributing factor to more U.S. deaths per year than any other weather hazard. This manuscript summarizes the world's first Chief Heat Officer's efforts to build local heat and health evidence. The places with the highest heat -related illness rates had hotter surface temperatures and/or higher proportions of people who were outdoor workers, Indigenous, and living in poverty or mobile homes. On hot and humid days, 7.8% (603 deaths) of the summer deaths per year were associated with the concurrent and preceding day's heat exposures. In response, Miami -Dade County is targeting heat interventions, lowering heat advisory thresholds, and considering new heat safety laws.