And the Ultra Warm version is 2.25 times warmer than their regular Heattech—so if you’re worried about being cold while layered up in these, don’t. There aren't too many thermal underwear ...

Long underwear — a.k.a. long johns, thermals, base layers ... looser clothes in cold weather — is my favorite way to keep warm when there’s windchill. When dining outdoors, walking in ...