The Early Show went to someone Thursday who certainly would know -- filmmaker and adventurer David Breashears, who's endured the coldest extremes, including a 1996 blizzard on the top of Mount Everest that claimed several lives.
Breashears told co-anchor Harry Smith it all begins with "the same thing we do when we're on a big mountain like Mt. Everest, when we open the door of the tent and look outside. Or you turn on the news and you look at the forecast. And you decide, 'Is it snowing? Is it raining? Is it windy? How cold is it?' And very importantly, how are you gonna spend your day? Inside or outside? Then you decide how to dress."
Then, said Breashears, "It's all about layers." And he noted that, "You're much more likely to layer if you can take it off when you get inside."
You start at the top -- your head -- with a polypropylene or wool hat or ski cap.
Also, keep your neck warm with a wool scarf or neck gaiter.
A fleece zipper jacket that goes up to your neck, and a lightweight down jacket that's not too puffy and has a drawstring waist would come next.
Then, and this is "often overlooked," Breashears says, "your hands. There's a lot of surface area on your hands. (They're like) five big cylinders. There's a lot of capillaries right near the surface of your skin, and your hands are sensitive. So, if your hands are cold, even if your body's not cold, you're going to feel cold. So, when I'm in the mountains, I wear gloves" -- ideally, lined, fleece gloves made out of a wind-stopping material. On a mountain, go for medium-weight climbing gloves that go over your wrist (with a gauntlet) (for ice-climbing).
Breashears advises that you watch out for your feet -- tight shoes usually make for cold toes. You need to keep them moving. Use leather-lined or Gore-tex, waterproof and breathable boots.
More things to keep in mind: Watch your coffee intake when heading outside.
There's nothing like a hot beverage on an empty stomach; it's hard to avoid in the morning. If it's going to be very cold, Breashears forgoes coffee and caffeine. In the mountains, he says they remember to have a good, hearty meal before they go out. He also advises to drink lots of water to keep hydrated during the brutal cold months. By following these practices, the body will generate enough energy to stay warm. The last thing you want to do is drink is alcohol: If you're really, really cold, you don't want to dilate the blood vessels.
Breashears says, off-the-mountain, leather or Gore-tex is great at buffering your body from harsh winds.
"When I'm high on Everest or in Tibet," Breashears says, "what keeps me ensure that I am staying warm is a wind-proof layer. If you're going to put the wool on, put on another layer."
Don't keep on any wet clothing, especially damp socks. Change into fresh, dry clothing when you're indoors to help yourself warm up. If you want a "sensory warm-up" and you plan to stay indoors, hold a warm mug. Breashears says holding a mug wont necessarily bring up your total body temperature, but it "creates a nice sensation, and it's comforting."