Participatory systems science to identify local adaptation strategies for extreme heat in King County, Washington

Extreme heat is a complex public health problem driven by interactions at the individual, community, health system, and policy levels. Participatory systems science engages interested parties to examine the interconnected factors driving heat-related illness and to develop locally tailored adaptation strategies. This article describes how local government agencies and community members from an area with high heat exposure in King County, Washington, engaged in the participatory systems science approach of group model building to co-develop extreme heat solutions during 2024?25. Recommended solutions included community education on heat risk; health system policies that increase access to health care; policy-informed infrastructure changes that expand access to green space; and lifesaving direct support, including distribution of cool kits to unhoused people and energy assistance programs. The insights generated can inform heat adaptation efforts across jurisdictions. The methods described offer a scalable approach to co-designing policies and interventions that can inform national and global climate resilience strategies to reduce health risks from climate-related events.