Rescuers in Phoenix Are Using Mobile Cold Plunges to Save Overheated Hikers

August 18, 2026

Move over, Wim Hof. Rescuers in Phoenix, Arizona, are using mobile cold plunges to save overheated hikers when temperatures soar. And now, members of the Phoenix Fire Department make sure to bring the devices—which look like a cross between a plastic tarp and a sleeping bag—along to every call in the spring and summer.

“We used to put ice packs into people’s armpits and groin areas, but we realized it wasn’t cooling them down quickly enough,” said Mike Johnson, a captain with the Phoenix Fire Department. “When a person’s temperature is that high, only a cold immersion will work.”

Thanks in no small part to Hof and his popular YouTube video series, cold plunges have, in recent years, become a cure-all for a wide range of maladies, from depression and anxiety to insomnia, as well as a useful tool to soothe sore muscles. Outside