Outdoor comfort in arctic cold relies on wicking moisture off skin

Published: Friday, January 18, 2008

NEW YORK - Cold-weather dressing used to be about warmth; now it's more about wicking. And choosing your base layer - what your parents called long johns - is one of the most important dressing decisions you can make before heading out to ski, snowboard, snowshoe or even take a cardio-pumping walk.

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This undated photo provided by Hot Chillys shows a men's technical waffle knit top made of 100% microfiber made by Hot Chillys. This waffle knit moves moisture away from the skin where there is direct contact, while the pockets in between trap warm air.

"The basic or fundamental principle of winter clothing is no cotton," says Justin Nyberg, research editor at Outside magazine.

"The most important insulation is the stuff right on your skin. Everything else you're putting on after that is helping to keep your insulation warm. ... If you pick the wrong base layer - a cotton shirt under a pricey jacket - you're still going to be cold when you get wet or when you sweat."

Wet and winter don't mix

Jennifer Husk, a licensed athletic trainer at Aurora Sports Medicine Institute in Milwaukee, Wis., builds her outdoor outfit around a synthetic under layer that acts as an insulator. On top of that she'll wear a polar-fleece mid layer and a water-repellent or waterproof outer layer. That mid layer is the one place she might wear a cotton sweater as long as the activity wasn't too strenuous.

"Cotton definitely absorbs perspiration, it's not taking it away from your body. When you're moving, it's fine but as soon as you stop, you're not - you just have wet clothes," Husk says.

Wet makes you feel cold, and if you're cold you run a greater risk of torn muscles, she notes.

Wool has a reputation that it'll keep you warmer if it does get wet, says Nyberg, but synthetics aim to alleviate wetness in the first place. "A synthetic dries faster, so it's good for aerobic or sweaty activities like skiing," he explains. "Wool probably keeps a little more heat and is a good option for a winter hike."

Steve Lee, vice president of sales at Hot Chillys, a staple brand of ski and sport stores, remembers wearing the traditional waffled cotton long johns every day as a kid growing up in cool climes. Later, smooth cotton styles were popular and those eventually morphed into silk.

Hot Chillys developed a fabric in the early 1980s that was a blend of wool and synthetic polypropylene. "The polypropylene was against the skin to pull moisture away, the wool was on the outside for warmth and to provide the absorption layer."

(Polypropylene is used as another word for polyester, Lee says. "We used that phrase because when you say polyester' to people, they think of leisure suits from the '70s.")

The brand shifted more heavily to polyester over the years, though, as microfiber technology improved, leading to a smaller fiber that can be woven more densely. The dense fabric, Lee explains, is thermal, wind resistant and can wick moisture away sooner.

"It's like sucking water out of a straw - if you hold the straw only halfway down, you don't get all the liquid," Lee says. "Microfiber holes are smaller so it happens more efficiently and earlier."

People want waffles

But even armed with new knowledge and materials, people wanted their waffle.

"I've been selling performance base layers for 20 years," Lee says, "and I'm still amazed at how many people will go out and buy that cotton waffle."

This year, Hot Chillys began to sell a "technical" waffle. "It looks the part, but it's 100 percent microfiber, hollow core synthetic. ... It's been well-received. I don't know if folks know what they're getting, but it looks very familiar to them." Lee says.

The waffles have some value: Moisture is moved away from the skin where there is direct contact, while the pockets in between trap warm air.

It's harder to regulate body temperature while participating in winter sports than summer ones, notes Dean Stoyer, director of U.S. media relations for Nike, because there surely will be variations in conditions within a single day.

Still, you don't need to pile on layers - using the right fabrics in the right order can keep them to a minimum. A Nike Pro garment made of its patented synthetic fabric called Dri-FIT is intended to be worn with only a jacket or snowpants over it. It targets the core body temperature instead of battling the elements, says Stoyer, himself a snowboarder. "I see people in the lodges pulling off layer after layer. You don't have to do that. Athletes are adopting a new way of dressing and weekend warriors are doing it more and more."

Style and substance?

But "warrior" isn't the look everyone wants.

Eesa is a line in its third year at retail, and there is an even emphasis on performance and style, says founder Stephen Cleary. Some of the more fashion-forward details are slimmer cuts, brass buttons and whipstitching.

"I started the company because when I was out snowboarding I noticed people in cotton hoodies, rugbys, T-shirts. I'd ask why they were wearing them and they'd say, I don't want to be seen in that other stuff,'" he says.

With wicking and fashion taken care of, Stoyer predicts the next evolution in the base layer will come in comfort. Many brands, including, Nike are trying to eliminate seams so base-layer garments won't irritate or rub the skin they're trying to protect.