Extreme heat is one of the leading causes of weather-related illness and death in the United States, causing more fatalities in a typical year than hurricanes, tornadoes, severe storms, and floods. Rising temperatures in recent decades have exacerbated heat-related health impacts as well as impacts to livelihoods and infrastructure. These impacts will likely continue to increase if action is not taken to understand exposure to heat impacts, who is most at risk, and what actions can be taken to reduce risk in the short- and long-term. To become more resilient to these events, communities across the U.S. are developing heat action plans and updating all-hazard plans to prepare for extreme heat’s impacts on people, businesses, and critical infrastructure. Many of these new heat plans have not yet been tested (or exercised). The National Integrated Heat Health Information System (NIHHIS) and NOAA’s Regional Collaboration Network are hosting this challenge to invite local governments, in close collaboration with community members and leaders, to develop Heat Tabletop Exercise Situation Manuals complete with realistic extreme heat scenarios to exercise heat action plans. In particular, the situation manuals should fuel tabletop exercises that build equitable resilience to extreme heat, linking shorter-term preparedness and response with longer-term planning and risk mitigation. The Challenge provides an opportunity for state, tribal, local, and territorial governments to work with community-based organizations and other key partners in developing situation manuals for novel heat tabletop exercises. Prizes will be awarded for up to ten (10) Situation Manuals.