A prolonged heat dome is producing record-breaking temperatures across the western United States and expanding eastward, triggering widespread heat alerts [1, 2, 3].
This weather event represents a significant public health risk because the U.S. currently lacks a federal disaster framework that classifies extreme heat as a major disaster [4, 5]. Without this classification, millions of residents face a gap in the federal disaster safety net during lethal temperature spikes.
The heat dome has already smashed all-time records in Montana and Utah [5]. Heat index values are expected to reach up to 115°F in some affected areas [3]. The system is currently impacting at least 21 states [3, 6].
Estimates of the population affected by these alerts vary by source. Some reports indicate more than 160 million Americans are under heat alerts [6], while other data suggests the number exceeds 200 million [4]. Additional projections state the heat dome could specifically affect 100 million Americans [5].
These current conditions follow a trend of increasing heat-related mortality. In 2024, extreme heat killed 2,394 Americans [4]. The current system is expanding its reach from the west toward the East, increasing the number of people exposed to dangerous temperatures [2, 3].
Local authorities continue to monitor the movement of the heat dome as it shifts across the country. Residents in the 21 states under warning are advised to take precautions against heat-related illnesses as the system persists [3].
“The U.S. lacks a federal disaster framework that classifies extreme heat as a major disaster.”
The scale of this heat dome highlights a systemic vulnerability in U.S. emergency management. Because extreme heat is not categorized as a formal federal disaster, the government cannot deploy the same level of resources and funding used for hurricanes or wildfires, leaving state and local agencies to manage the crisis with limited federal support.
