The future will be warmer with more tropical days, heat stress and related impacts for the healthy and liveable city. This is clear from many scientific studies and papers. Yet many local governments in the Netherlands claim to have insufficient understanding of the importance of these impacts in order to make the necessary step to climate adaptation and to take practical actions to manage the risks associated with rising heat levels. They struggle with defining the urgency of heat stress and finding good arguments for the need to adapt urban environments to rising temperatures. In order to provide urban professionals with reasons to adapt their urban environments to heat, we analyzed the potential impacts of urban heat from international policy reports and scientific literature. We summarized the impacts in a mind map. This map visualizes the large number and variety of heat-related risks. They can be subdivided into risks for health, open space, liveability, water and infrastructure networks. We believe that this mind map provides useful insight into the reasons to take heat adaptation actions. It can also be a helpful visual for urban professionals in outlining the reasons to take action for heat adaptation.