Layering your clothing is a tried-and-true way to ensure your comfort in the outdoors. The beauty of this simple concept is that it allows you to make quick adjustments based on your activity level and changes in the weather. Each layer has a function. The base layer (against your skin) manages moisture; the insulating layer protects you from the cold; the shell layer (outer layer) shields you from wind and rain. You simply add or subtract layers as needed.
Base Layer: Moisture Management .......This is your next-to-skin layer. More than any other layer, the base layer helps regulate your body temperature by moving perspiration away from your skin.
Your Middle Layer: Insulation.......The insulating layer helps you retain heat by trapping air close to your body. Polyester fleece vests, jackets and tights are classic examples of insulation ideal for outdoor activities.
Your Shell Layer: Weather Protection.......The shell or outer layer protects you from wind, rain or snow. Shells range from pricey mountaineering jackets to simple windproof jackets, but most are designed to block precipitation and hold in your body heat while allowing water vapor to escape.