ALBUQUERQUE, N.M. — On a recent Friday in Albuquerque, New Mexico, as triple-digit temperatures stretched into the evening, a 69-year-old man collapsed in his home.

His body temperature hit 107.7 degrees by the time emergency responders whisked him to the University of New Mexico Hospital. Nurses and emergency physicians began a process that has become familiar, preparing a device the size of a minifridge that rapidly cools and regulates body temperature by funneling cold fluids to pads that cover a patient’s abdomen and thighs.

Workers dumped ice on his body as part of a last-ditch effort to curtail his heatstroke. It was too late. The man’s blood pressure had plummeted, and he suffered a heart attack.

Less than 24 hours later, he was dead. Extreme heat, intensified by climate change, has blanketed much of the United States this summer, killing more than a dozen people in Oregon in recent days. Large parts of California, Nevada, Arizona and Utah have been under excessive heat warnings, which local officials believe contributed to more than 90 deaths in the West this month.

The consequences are increasingly playing out in the nation’s emergency rooms, where medical workers are confronted with heat-stricken patients whose soaring body temperatures can be fatal if not addressed quickly. Around 2,300 people died from heat-related illnesses in the United States in 2023, triple the annual average between 2004 and 2018. Nearly 120,000 heat-related emergency room visits were.