MINNEAPOLIS — It’s not the heat, it’s the humidity, goes the old saying. For the tens of millions of Americans currently trapped in the deep freeze: It’s not the cold, it’s the wind.
Air temperatures plunging into the negative teens, 20s and even 30s are bad enough. But add wind speeds of even a few miles per hour, and what’s already deeply unpleasant becomes downright dangerous.
“It’s not so much the absolute cold, though that’s certainly not pleasant either,” said Mark Seeley, a climatologist for the University of Minnesota. “But what the wind does when it starts blowing it around is force the cold air onto whatever it touches. Whether it’s human skin or a car engine, the wind pushes away the warmth being generated and replaces it with cold.”
Thus the popular term “wind chill,” which a couple of Polar explorers originated in 1945 to differentiate between the actual temperature, and the temperature that it feels like thanks to the wind. For instance: In International Falls, Minn., along the Canadian border, it was forecast to reach an air temperature of 30 below zero early Monday. But wind gusts made it feel more like negative 60.
“Fighting a fire on a night like that, a lot of our guys would rather do recon in the burning structure than man the hoses,” said Jim Hultman, a veteran firefighter in International Falls, frequently one of the coldest spots in the nation. “I’m not kidding. Because at least you’re warm.”
Hultman said cold winds ice up the nozzles, slow the water streams and blow an icy mist onto the firefighters. “It’s just miserable,” said Hultman, 59, adding in an interview that he’s “nine shifts away from retirement and then I’m headed someplace warm for a few months.”
Severely low wind chills are a serious threat to the human body. “Really, the best advice I can give is don’t go outside at all unless you absolutely have to,” said Douglas Brunette, an emergency room doctor at Hennepin County Medical Center in Minneapolis. Skin exposed to such wind chills can develop frostbite within five minutes; hypothermia comes close behind.
“I have seen frostbite occur through clothing,” Brunette said. “It’s not enough just to be covered. You need clothes made for the elements. You need to repel the wind.”