A state-level ecological analysis presented at ATS 2026 finds that U.S. critical care infrastructure is not keeping pace with the growing threat of extreme heat.
The study cross-referenced heat-related deaths from 2021 to 2023, adult ICU bed capacity, and CDC Heat and Health Index scores to identify mismatches between climate vulnerability and critical care access.
Arizona recorded the highest absolute burden: 733 heat-related deaths and a deaths-per-ICU-bed ratio of 0.344, despite having moderate ICU capacity. Nevada was also flagged with the highest heat-related death rate (6.37 per 100,000) and a high vulnerability index.
Eight states now meet the definition of "critical care deserts," with 0.2 ICU beds or fewer per 1,000 adults. Four high-vulnerability western states-Oregon, Washington, California, and Idaho-are among them.
Authors warn that infrastructure alone cannot compensate for extreme vulnerability when pre-hospital systems fail. They recommend integrating Heat and Health Index scores into ICU capacity planning and designating ICU capacity as climate-critical infrastructure to guide federal investment.
Source: Siddiqui K et al. ATS 2026.