Much of our current understanding of extreme heat is based on short-term events like heat waves (I.e., acute heat), but across much of the world, people are exposed to dangerous heat for several months at a time. We use chronic heat as a term to bring attention to an overlooked region of the world. Current research and practice has missed areas facing chronic heat, including related health impacts. We put forward a framework to characterize, understand, and manage chronic heat. We developed new metrics to identify regions that experience chronic heat and demonstrate how current definitions fall short of recognizing these chronically hot regions. We demonstrate how exposure and risk accumulate over time and across spaces of exposure (e.g. at home, work, commuting, recreation). We offer paths forward for coordination within and outside of governments and how acute heat solutions can be adapted to address chronic heat impacts. Lastly, we present six key research priorities focused on data sharing and gathering, better tracking of heat-health impacts, and broader coordination among diverse groups to better address chronic heat. We encourage practitioners, government officials, researchers, and the public to utilize this framework to prepare for current and future chronic heat challenges.