When the goal is to stay warm and dry while skiing/boarding, the trick is to dress in multiple, lightweight layers.

The beauty of layering is that you can shed and add clothing as conditions or your exertion levels change. Thanks to new high-tech fabrics, personal climate control is now a reality as body-warmed air is trapped between layers of clothing while moisture vapor from perspiration is allowed to escape.

A layering system usually includes three components.

• An inner moisture-wicking layer
  To keep the body warm during high-energy activities, clothing should transport moisture away from the skin, to the outer surface of the fabric where it can evaporate. Companies are now using new ultra-light fabrics like CoolMax and Thermastat in their long underwear. These materials wick moisture from the skin and move it away, so start with this as an inner layer. Also look for garments made from the new stretch fabrics for better fit and performance.

• A middle insulating layer
  Your next layer should be a lightweight stretchy insulator such as a breathable fleece sweater or vest. While you might not need it once you're warmed up, you'll appreciate a cozy top on your descent or on the ride home.

• An outer shell layer
  The final part of your cold-weather wear should be a lightweight and versatile shell jacket that will function for highly aerobic as well as less strenuous activities, depending on what you layer under it. With the creation of The North Face's three-layer Gore-Tex and other innovative fabrics, today's shells are ultra lightweight, while remaining waterproof, windproof, and breathable. Activent, a new highly breathable shell-fabric option (also by The North Face), is water-resistant, and may be a good option if weather conditions are fair and you're really moving. For aerobic activities, a shell's ventilating features are particularly important. Look for underarm zippers as well as venting pockets and back flaps.

It's important to keep several things in mind as you consider the numerous styles and fabrics available for each layer.

• Garments should be lightweight and compressible.
  If you need to shed a pullover, for instance, it should easily fit into a fanny pack or rucksack.

• Look for high-quality synthetic fabrics that are breathable.
  Natural fibers such as cotton and wool retain moisture, leaving you damp and cold.

• Choose a shell that is large enough to fit comfortably over several layers.

• Select garments that are versatile
  Clothing should adapt to changes in the weather and be useful for a variety of activities.

Additional variables to consider include your fitness level, your body type, the activity you'll be doing, and where you'll be doing it. Do you chill easily? Sweat a lot?

Highly aerobic activities such as cross-country skiing and running require very different clothing systems from sports such as snowboarding and downhill skiing, in which your energy output constantly fluctuates. And if you're heading into the backcountry or will be far from a heated shelter for any extended period, your clothing will be as important as any piece of equipment you have. It can literally mean the difference between life and death.

The weather, of course, is one of the most significant factors in what you decide to wear. Heeding the weather forecast can help ensure an enjoyable excursion. Ignoring weather can make you rue the day you first strapped on skis or boards. And even if you've checked the weather report, you should always be prepared for unforeseen changes, since weather, especially in the mountains, can be very unpredictable.