B96-01 Heat Vulnerability and ICU Capacity: State-level Disparities in U.S. Critical Care Resilience to Extreme Heat, 2021-2023

Rationale Extreme heat events are intensifying due to climate change, causing multi-organ dysfunction and exacerbating chronic disease, yet the relationship between heat vulnerability, ICU capacity, and mortality remains poorly characterized at the state level, limiting climate adaptation planning. Methods We conducted a cross-sectional ecological analysis linking: (1) heat-related deaths (ICD-10 X30) from CDC WONDER (2021-2023); (2) adult ICU beds per 1,000 adults from HHS Protect (2021); and (3) Heat and Health Index (HHI) scores from CDC/ATSDR (2024). We calculated deaths per ICU bed ratios as an ecological burden indicator. Mortality analyses included six states meeting CDC suppression thresholds (≥10 deaths); ICU capacity mapping included all states and territories. Results Heat-related mortality totaled 1,620 deaths across six western states. Arizona showed the highest absolute burden (733 deaths, 6.89 per 100,000) and deaths per ICU bed ratio (0.344), despite moderate ICU capacity (0.4 beds per 1,000 adults; national mean=0.31). Nevada demonstrated the highest death rate (6.37 per 100,000) with high vulnerability (HHI: 0.658). Eight states had critically low ICU capacity (≤0.2 beds per 1,000 adults), including four high-vulnerability western states: Oregon (HHI: 0.620), Washington (HHI: 0.556), California (HHI: 0.575), and Idaho (HHI: 0.553), creating ‘critical care deserts’ where capacity is disproportionately low relative to population risk. Conclusions Geographic mismatches between climate vulnerability and ICU capacity reveal clear targets for federal resource allocation. Arizona’s capacity-mortality mismatch demonstrates that infrastructure alone cannot offset extreme vulnerability when pre-hospital systems fail. Integrating HHI scores into ICU capacity planning could enable vulnerability-adjusted standards. Current federal and state heat action plans, including the US National Heat Strategy (2024-2030), lack critical components for care surge capacity. Our findings support designating ICU capacity as climate-critical infrastructure and prioritizing investment through HHS Hospital Preparedness and FEMA Climate Adaptation funds to address identified critical care deserts before they face catastrophic heat events.