Dutch municipalities tackling climate change adaptation to heat stress through mainstreaming across sectors

As climate change accelerates, adapting to heat stress means preventing excess deaths, increased healthcare costs, reduced productivity, and damaged infrastructure and buildings. In cities, the urban heat island effect exacerbates these impacts. Adapting to heat stress requires action by a multitude of actors in different domains, including infrastructure and building owners, health care and social workers, and vulnerable inhabitants. While there is research on heat stress adaptation by single sectors, there is a significant knowledge gap regarding heat adaptation across sectors. To contribute to bridging this knowledge gap, we answer the following research question: To what extent and how are municipalities in the Dutch Province of Overijssel mainstreaming heat stress as part of their adaptation efforts? To answer this question, we combine action-oriented research employing the Institutional Analysis and Development Framework in a Dutch municipality, with a survey conducted among 15 municipalities located in the same province. Our research identifies two major challenges. First, the implementation of heat adaptation remains limited. Second, we identified two challenges regarding mainstreaming, namely a mismatch between the responsibility of heat adaptation in the built environment vis-a`-vis the health care sector, and a lack of information on vulnerable groups that makes cross-sectoral collaboration more difficult. Thus, the extent to which heat adaptation is being mainstreamed as part of municipalities' efforts to adapt the built environment is still quite limited and heat stress management at the intersection with the health care sector remains mostly absent, leaving vulnerable groups exposed.