"Extreme temperatures claim more lives than any other weather-related event, posing escalating socio-technical and governance challenges that few urban communities have addressed in a systematic, coordinated and comprehensive way. Scholars have only recently begun to investigate the granular scales at which distributions of thermal risk are produced, people’s individual subjective thermal experiences and environmental justice dimensions of the hazard. Advances in research pave the way for concomitant improvements in management and policies, but bridges are needed to connect the thermal vulnerability knowledge base with place-based protective practices that are climatically, politically and culturally appropriate. The research presented in this paper uses actor–network theory (ANT) to describe the planning phase framework of a socio-technical collaborative for managing thermal extremes. The Thermally Resilient Communities Collaborative (TRCC) is a framework for planning and test-bed design phases of a thermal management system. Drawing lessons from two case studies, the framework examines how socio-cognitive spaces for collaboration change with technical and policy disruptions, and provides a way to design experiments that test how technical and governance interventions can enable collective action around urban thermal management."