The intensifying and expansive heat wave affecting around 150 million people in the United States from Wisconsin to Washington, DC, bears the hallmarks of human-caused global warming.

Heat waves are getting more dangerous with climate change — and we may still be underestimating them By . Andrew Freedman. Updated Jun 23, 2025, 1:10 PM ET. PUBLISHED Jun 23, 2025, 12:47 PM ET.

Extreme heat kills more people in the United States than any other weather hazard, and the risk of longer and more frequent heat waves is only expected to increase as climate change worsens. Heat ...