Effects of cold on the body
It’s been tough going this winter. Extreme cold and wind chill can cause more than chilly toes. Especially if you’re not protected.
We hear it every day. During every weather forecast in winter. The windchill factor. But what exactly does it mean?
“It’s really an extra warning for people to understand what windchill is and the fact that wind can increase your odds of danger in a cold situation very very rapidly.”
And Stephen Chung knows what he’s talking about. At Brock University, he’s known as Dr. Freeze. In the laboratory he studies the effects of extreme temperatures on the body: “It has a lot of applications to everything from athletes through to different occupations, firefighters who may be in extreme heat to individuals who may be in a survival situation in the North Atlantic.”
His climate lab allows him to create his own conditions. A temperature chamber with humidity control as well as oxygen levels can produce temeratures from minus 30 to plus 50. An immersion tank is another tool used in his studies. In explaining wind chill, Chung says it involves something called convective heat loss: “What happens is your body will send out it’s heat. It will lose heat and it will warm up that immediate air layer or water layer around you. It’s the same thing that a wet suit does. It traps a warm layer of water next to you. You heat that up and that insulates you. Now what wind chill does is it comes along and removes that warm air that you’ve just created or that warm water.”
And that’s why we lose heat a lot faster in wind or water with a current. In these extreme conditions, the body strives to protect it’s main organs. The heart and lungs. By constricting blood vessels in our extremities. That tingling and numbness in our fingers and toes. This Purdue Pegboard is a standardized test for manual dexterity. In the warmth of the lab, our volunteer Phil scores 36 in 60-seconds. But outside, dressed in light pants and a t-shirt it’s a different outcome. After only 5-minutes, Phil is visibly cold.
Stephen says: “When you’re shivering, what the body is really doing is the muscles are firing. But instead of producing really useful work it’s generating a lot of extra heat. And that heat is warming yourself up.”
But not to the extremities. In just a short time, phil’s losing the function of his hands. Scoring only 25. For us, it could be the ability to put a key in a lock, or do a zipper on a coat. And though he was a good sport about it, the cold can take a toll on cognitive function and decision making.
We do all feel the cold differently. Some have a greater sensitivity to extreme cold or extreme heat. How much is psychological is unclear. But Stephen Chung says that is the next frontier of his research.