CDC Reports Surge in Heat-Related Emergency Department Visits During 2026 Heat Dome

A new CDC Morbidity and Mortality Weekly Report (MMWR) highlights substantially higher heat-related emergency department visit rates during a 10-day heat dome affecting much of the eastern, midwestern, southern, and south-central United States from June 28–July 7, 2026.

About 221 million people, or 65% of the U.S. population, experienced at least one day of major or extreme HeatRisk across 42 states and the District of Columbia. ED visit rates exceeded the 2018–2025 95th percentile benchmark in most affected HHS regions, with the highest rates occurring around the July 4 holiday.

Men ages 26–54 had the highest rates in six regions, underscoring the value of timely surveillance and heat warnings for targeted prevention. Read the MMWR here.