HeatWise DC—a continuation of the HeatWise Policy Partnership launched in 2024—brought together 62 cross-sectoral leaders to confront the rising threat of extreme heat. Held in Washington, DC, the three-day event focused on rural vulnerability; national security and defense; and finance, insurance, and industry. Participants highlighted that while there are existing tools and knowledge to address heat, policy, funding, and delivery systems remain disconnected from the realities on the ground.

Extreme heat is increasingly causing disruptions to critical infrastructure across sectors. With more frequent and intense heatwaves, infrastructure designed for milder conditions is being stressed beyond its capacity, resulting in higher maintenance demands and limited effectiveness of mitigation measures.

This report examines the landscape of extreme heat management among United Nations entities and International Organizations for the first time, identifying challenges, opportunities, and strategies for improving collaboration and governance to support the United Nations Secretary-General’s Call to Action on Extreme Heat.

This synthesis report identifies best practices and persistent challenges to provide a structured framework for improving heat resilience based on evaluations of heat action plans from six countries: Australia, Canada, France, India, the United Kingdom, and the United States. It advocates for an adaptable governance framework, proposing that national guidance related to Heat Action Plans incorporate adaptable core elements, such as standardized heat risk definitions, clear agency roles, multi-sector coordination, and early warning systems.

This narrative analysis highlights how 12 countries are confronting the realities of extreme heat through diverse governance models, partnerships, and innovations. The case studies span multiple regions and development contexts—Argentina, Australia, Bangladesh, Canada, Ecuador, Egypt, France, India, Senegal, the Republic of Korea, the United Kingdom, and the United States, offering a cross-cutting view of what is working, where gaps remain, and how national strategies are evolving in the face of escalating climate threats.

Extreme heat is an escalating public health and economic threat, particularly in rural, low-income communities across the Southeastern United States. In these areas, aging infrastructure, high energy burdens, and chronic health disparities intersect to create acute vulnerability during periods of excessive heat. Cooling Communities is a seed initiative that brings together community leadership, trusted faith-based institutions, and financial innovation to explore scalable, locally rooted strategies for heat resilience.

Exertional heat illness poses a significant risk for workers, athletes, and military personnel participating in outdoor activities during hot weather. An important component of heat safety is monitoring environmental conditions through heat stress indices like the wet bulb globe temperature (WBGT), which accounts for factors such as air temperature, humidity, wind, and sunlight, and adjusting activity as conditions get progressively hotter.

Extreme heat directly impacts health and can exacerbate substance use. Rural communities face high risks due to those areas’ higher rates of heat-related hospitalizations and disproportionate effects of substance use. This commentary explores the connection between heat and substance use in rural communities and proposes policy, research, and practice recommendations that can be tailored to fit the local rural context.

The HeatWise Policy Partnership Summit is a key component of a cyclical two-year program that encompasses stakeholder engagement, event planning, biannual convening, reporting key findings, and outreach to policymakers.

Increasing temperature will impact future outdoor worker safety but quantifying this impact to develop local adaptations is challenging. Wet bulb globe temperature (WBGT) is the preferred thermal index for regulating outdoor activities in occupational health, athletic, and military settings, but global circulation models have coarse spatiotemporal resolution and do not always provide outputs required to project the full diurnal range of WBGT. This article presents a novel method to project WBGT at local spatial and hourly temporal resolutions without many assumptions inherent in previous research.