S N O W B O A R D I N G

Clothing:

The layering system is a must for outdoor sports and is particularly suited to ski and snowboard apparel.

A breathable base layer is essential to wick moisture generated by exerting yourself while descending, and it prevents you from feeling cold once you are on a chairlift. Long thermal underwear made from synthetic fibers are a suitable option, but merino wool is even better for the breathability and warmth it provides, even when wet.
A mid-layer is worn to maintain your body heat. It could be a fleece, or a light insulated jacket worn over your thermal underwear. Your ski/snowboard jacket is often already insulated with a fleece lining or a synthetic or down filling, so you should adapt your mid-layer accordingly.
The outer-layer is your ski/snowboard jacket. As mentioned above, your jacket can often have a fleece or synthetic lining, or for warmer jackets a down quilting. Your jacket must be waterproof and breathable, to protect you from the wind and snow.
Layering is simplified for the lower half of your body as there is less perspiration to deal with. Like snow jackets, snow pants are often lined and warm. You can therefore wear just your snow pants, or wear long underwear underneath, depending on the weather conditions.