It may shrink your bank account, but no jacket on the market regulates heat as well as the Thrym. The PrimaLoft insulated shell is equipped with body-mapped pods of goose down on the interior that retain warmth without adding bulk. Unzip the jacket's ducts and those pods help push out heat. Its four-way stretch holds up to all the rigors of lift skiing without limiting movement. [$900; hellyhansen.com]