-
Feb 15, 2008 6:12 am US/Mountain
-
Digg |
Facebook |
E-mail
|
Print
Cold Hits Humans Hard
Good Question: How Does Cold Affect Us?
DENVER (CBS4) ―
"Oh, we've had snowmaking with 40 below zero for sure," says Vail snowmaker Dave Tucholke.
He's brave. So are the folks at the National Ice Core Laboratory at the Federal Center in Lakewood, who handle arctic ice samples that can cost as much as $20,000 to obtain.
They're kept in a freezer at close to minus 40 degrees.
"They're much better before their dropped," says lab manager Todd Hinckley.
They all have to know now to deal with cold.
The University of Colorado Hospital's Dr. Kennon Heard knows cold's effects.
"Our body does a really good job of trying to regulate body temperatures," Heard said.
The control mechanism is in our hypothalamus gland, deep in our brains. When it finds out we're cold, it tells our muscles to shiver, our blood vessels to contract - which can make us look blue - and the little muscles around our body hairs to contract.
That may be a carryover from our hairier days. It works better for animals with fur coats than it does for us.
"Well really your body works, is designed to work, at a set temperature. And all the reactions that take place in the nerves and the muscles are really temperature dependent," says Heard.
Hinckley knows that.
"People when they get cold, they get stupid and they drop things and they often don't realize themselves that their attentiveness is deteriorated."
One thing that happens is a reduction in blood volume.
"The amount of water that's in the blood will actually drop. So they actually become effectively dehydrated," says Heard about what happens to people.
It's actually water that helps keep us warm in the first place says Chemistry professor Doris Kimbrough of the University of Colorado Denver.
It's what's called, heat capacity and water has a bunch of it.
"It has a heat capacity probably greater than any other substance," says Kimbrough. "Because we're a lot of water, we can hold that heat."
But lose that heat by say - jumping in an icy lake in a polar plunge and away it goes. Water will draw the heat out of you in a hurry. Drop more than three degrees and it's too hard for our bodies to heat that water inside us enough to bring us back to normal.
"We can't generate enough energy through metabolism to get it back up to the 98.6. So you need some kind of external source," says Kimbrough.
That's when you try a blanket or a nice warm fire. And forget the alcohol, because while it may feel warm going down, it actually opens those blood vessels your body is trying to close.
(© MMVIII CBS Television Stations, Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)