Whether you’re training for a ski mountaineering race or just sick of shivering on your morning commute, staying warm and dry is objective number one. The base layer you choose to wear while doing battle with the elements can’t guarantee success, but it sure as hell can guarantee ruin. A wide (and widening) range of materials and styles also makes it easy to get overwhelmed. But have hope. New synthetic fabrics offer amazing moisture-wicking properties, while merino wool is experiencing a renaissance with temperature regulating properties that are borderline miraculous. We’ve done the leg work to find the best base layers for every outdoor activity and situation for upcoming winters, falls and springs.