Dangerous Extreme Heat Event Rattles Half of the Continental United States June 24, 2025

A crushing early-season heat wave is currently impacting 174 million people in the United States, from the Great Plains to much of the East Coast. As human-caused climate change continues to get worse, these dangerous extreme heat events are becoming more frequent and more deadly. This particular heat wave is so dangerous due to high temperatures being coupled with high humidity, causing health-harming wet-bulb temperatures across the US. When humidity is high enough, humans can no longer cool down by sweat alone, as the high humidity prevents sweat from evaporating. Heat exhaustion and heat stroke are real threats to nearly half the United States population, particularly elderly folks and those living in previously red-lined areas without tree cover or proper access to cooling systems or cooling centers. Extreme heat is even more deadly when the power grid is put under stress due to high demand, causing rolling blackout and grid failures that can lead to hospitalizations while utility companies continue to rake in profits.

PSR is actively working to protect the most vulnerable populations from extreme heat. This week PSR will be testifying in favor of OSHA extreme heat protections for workers and soon will be participating in a fly-in to DC to save the Low Income Home Energy Assistance Program (LIHEAP). To learn more about how you can protect yourself, your loved ones, and vulnerable neighbors from the worst health impacts of extreme heat, visit PSR’s Extreme Heat resource page.