Smartwool’s Merino 150 Base Layer Bottoms offer impressive warmth because they’re high-quality 100% merino wool construction. 32 Degrees Women’s Cozy Heat Base Layer is stretchy, comfy, and fits well ...

Whether you’re into snow sports or simply want to prepare for winter weather, base layers can help insulate heat while wicking sweat away from your skin. Those base layers can include thermal ...

The best kept secret about my winter wardrobe — until now, I guess – is that half of it is invisible. Between December and March, I rarely leave the house without a base layer (or thermal underwear, ...

Over the past few weeks, I had the pleasure of expanding my collection and testing a variety of thermal pants and tights while plodding through slush, skating around an outdoor rink, and even cycling ...

Thermal underwear is known by many names — long johns, base layers, long underwear, skivvies, or even britches (for my Southern friends). No matter what you call them, they are a staple for anyone ...

Whether you’re hiking icy trails or hitting the slopes this winter, high-quality thermal underwear is a must. The best thermal underwear won’t just keep you warm and cozy, either—it’ll also help you ...

Long underwear — a.k.a. long johns, thermals, base layers, or whatever else you want to call the cozy, body-hugging tops and bottoms worn beneath looser clothes in cold weather — is my favorite way to ...

Our product picks are editor-tested, expert-approved. We may earn a commission through links on our site. Why Trust Us? LET'S BE FRANK: Thermal underwear is arguably the least sexy type of underwear ...

We independently review everything we recommend. We may get paid to link out to retailer sites, and when you buy through our links, we may earn a commission. Learn more› By Trey French Trey French is ...