BACKGROUND: This article describes the first Community Assessment for Public Health Emergency Response (CASPER) rapid needs assessment project to be conducted in Wisconsin. The project focused on extreme heat preparedness. METHODS: Fifteen teams conducted household surveys in 30 census blocks in the city of Milwaukee, Wisconsin. RESULTS: Survey results indicated that the majority of households were unaware of the location of a nearby cooling center. Although the vast majority of households reported some form of air conditioning in their house, over half felt too hot inside their home sometimes, most of the time, or always. DISCUSSION: The community partnerships ensured that this project was conducted with local partner input and that the data could be used to inform extreme heat response.