Proper layering maximizes your outerwear's efficiency and allows you to adjust to climate changes; here's a recommended system.
- Base layer. Against your skin, wear something soft, comfortable, breathable, and absorbent, such as silk, polypropylene, Capliene polyester (from Patagonia), or Thermax (from DuPont).
- Mid-layer. The mid-layer consists of cotton jeans and a long-sleeved shirt. Cotton is comfortable and breathes, ushering body moisture away from your skin. Any moisture held against the skin will chill you.
- Insulation. In cold weather, layer insulation atop the cotton. Insulation provides loft or "dead air," which holds in body heat. Insulation can be worn as a separate garment, sewn inside the outerwear, or as outerwear itself. Insulating materials include down, synthetic down, wool, synthetic wool, and polarfleece. Weather conditions, activity level, and personal preference determine which of these options you choose.
- Wind protection. In windy conditions, you'll also need wind protection, such as a layer of breathable, wind-resistant nylon. (Keep in mind that if even one layer isn't breathable, you've negated the breathability of all the other layers.)
- Outerwear. The final layer is, of course, outerwear. Besides a coat to cover your torso and thigh, you may also need leg protection, such as waterproof chinks and gaiters. Smooth leather chaps ward off cold, wind, and some moisture, but aren't completely waterproof. (For more on outerwear, see "Trail-Tested Outerwear," The Trail Rider, January/February '10.)