Heat is a dangerous hazard that causes acute heat illness, chronic disease exacerbations, adverse pregnancy outcomes, and a range of injuries. Risks are highest during extreme heat events (EHEs), which challenge the capacity of health systems and other critical infrastructure. EHEs are becoming more frequent and severe, and climate change is driving an increasing proportion of heat-related mortality, necessitating more investment in health protection. Climate-resilient health systems are better positioned for EHEs, and EHE preparedness is a form of disaster risk reduction. Preparedness activities commonly take the form of heat action plans (HAPs), with many examples at various administrative scales. HAP activities can be divided into primary prevention, most important in the pre-event phase; secondary prevention, key to risk reduction early in an EHE;and tertiary prevention, important later in the event phase. After-action reports and other postevent evaluation activities are central to adaptive management of this climate-sensitive hazard.
Keywords: climate change; disaster risk reduction; extreme heat event; heat action plan.