Back in the day, mom made sure you donned your wool long johns before sending you out in the snow. One sled ride later your clothes were soaked through, but at least you smelled like wet dog.

These days, the snow savvy recommend high-performance, hydrophobic, moisture-wicking synthetic long underwear. No more ice-encrusted, eau de canine clothing for this generation of winter sports lovers.

From hiking trips to snowboarding, when it comes to winter sports, staying dry and protecting yourself from the wind is everything.

No one knows this better than Liv Arnesen and Ann Bancroft, two women who intend to make history by trekking across Antarctica.

Bancroft and Arnesen have selected their wardrobe to be tough enough for the tundra. They’ll be camping in icy conditions, so layers including a down jacket, pullovers with wicking (a moisture-repellent material), camp pants with a high back, and long underwear are essential.

While wicking garments are not new, the variety of these moisture-repellent products has increased substantially in recent years. Underwear, socks, gloves, hats, vests, camisoles — even bras can be found in this moisture-resistant fabric.

These garments also come in a range of prices. A top-bottom set of long underwear will run you anywhere from $40 to $150. The top-of-the-line stuff is generally superior to the bargain pieces, says Kelly Knight, store manager of Ski Chalet in Arlington, Va.

Do you need to spend top-dollar to stay dry? That depends on what you plan to do, says Knight. The occasional snowshoer may not want to make same investment as an avid skier.

It also depends on how much you exert yourself at winter sports. That’s because perspiration is a factor even when the weather is so cold you can’t imagine how it could be, writes Jerry Cinnamon in The Complete Climber’s Handbook. For this reason, what’s underneath is generally more important than what’s on top.

So before you drop serious cash on the latest Gore-tex jacket, consider what’s closer to your heart. “You could have the most expensive, highest-performing parka in the world, but if you don’t have the proper fabric next to your skin, you’ll be miserable,” says Knight.

If you take proper care with your first layer, you may have some wiggle room with the second and third. A second layer is usually more wicking fabrics or, in warmer temperatures, the old standby wool, says Cinnamon. A third layer may not be necessary if temperatures are over 20 degrees. Meanwhile, your outer “shell” should be as much for wind protection as warmth.

When it comes to wind protection, use your head, advises Bancroft. “I wear several layers on my head because your head is sort of the stove pipe,” she says. To lock in heat, she wears a facemask, a headband for added protection around her ears, and a hat on top of that.

Careful planning is the key to maximum comfort in extreme winter weather. “Since it is possible to overdress, you want the versatility of layers,” says Jennifer Feldman, assistant buyer of the Ski Center in Washington, D.C.

Try the layers on together in the store before you buy them. You’re looking for clothing that will give you the greatest warmth and flexibility in movement.