Staying cool in a changing climate: Reaching vulnerable populations during heat events

► We conduct case studies of heat-related health behaviors in four U.S. cities. ► Interviewees explain barriers to basic cooling strategies such as fan use. ► Intergenerational and peer relationships affect heat-related health among seniors. ► Ongoing planning may best support uptake and maintenance of key health behaviors. ► We inform interventions to protect vulnerable populations in a changing climate.