For those who want a warm core without the bulk of a jacket. The wool insulation adds warmth without weight and keeps working even when damp, which counts in the wet, heavy snow and drizzle you can hit at Whistler Blackcomb. Stretchy side panels let you move freely when you’re skiing or riding, and the wind-resistant shell cuts the chill on the chairlift. It packs down small, so it works as a mid-layer under a shell or as a stand-alone layer on mild spring days.