Base layers
Credit: Photograph by Levi Brown

Yeah, outerwear gets all the credit, but it's the layers you wear underneath that provide support and core warmth during winter activities. All have their uses, so choose wisely. They should be lightweight, snug-fitting, and made from serious moisture-wicking materials. Polyester and nylon are good; merino wool is best. [RLX Down Vest, $185, (left); Victorinox Glacier Full Zip, $250, (left); Rab MeCo 120 Tee, $85, (left); Rab Aeon Plus Zip, $55, (right); Patagonia Capilene 3 Midweight Zip, $60, (right)]