10 Best Thermal Underwear 2026 in the United States

The WEERTI Thermal Underwear for Men is designed to keep you warm and comfortable during cold weather, making it a solid choice for anyone needing reliable base layers. Made from a blend of 92% polyester and 8% spandex with a fleece lining, this set offers good insulation by trapping body heat while staying lightweight. The snug fit is like a second skin, which helps minimize heat loss and works well under various types of clothing, from casual wear to more formal outfits.

One of its strong points is the moisture-wicking fabric that effectively pulls sweat away from the skin, keeping you dry and preventing that uncomfortable clammy feeling. The material also stretches in all directions, allowing freedom of movement without feeling restrictive, and the seams are designed to be durable, lowering the risk of tears during active use.

This thermal underwear performs well for men seeking a comfortable, warm, and moisture-managing base layer suitable for winter activities or simply staying cozy indoors.

The Cuddl Duds Women's Thermal Underwear set is designed to keep you warm and comfortable during cold weather. Made primarily of polyester with some spandex, it offers a soft, brushed fleece inside for warmth and a sleek outer layer that feels smooth against the skin. The heavyweight fabric and dense knit provide good insulation without feeling bulky, making it a practical base layer to wear under clothes or on its own while lounging. Thanks to the spandex stretch, the fit is flexible and moves with you, which is great for staying comfortable on the go.

It also includes thoughtful features like thumb holes on the sleeves and a tag-free label to avoid irritation. The moisture-wicking fabric works well to pull sweat away from your skin, helping you stay dry during activity, while the material blocks over 50% of UV rays, adding extra protection if you’re outdoors. Weighing about 15 ounces for the set, it’s substantial enough to provide warmth but not overly heavy.

This thermal underwear is suited for women looking for a cozy, practical base layer that balances comfort, moisture management, and stretch for everyday cold-weather use.

The WEERTI Thermal Underwear for Women is designed as a base layer to keep you warm and dry in cold weather. Made from 92% soft polyester and 8% spandex with a fleece lining, it offers a cozy feel and good insulation while remaining lightweight. The fleece lining adds warmth without bulk, which is great if you want to layer under your jackets or sweaters. Its four-way stretch fabric provides flexibility, hugging your body nicely to allow easy movement without feeling tight or restrictive.

A strong point of this thermal underwear is its moisture-wicking ability, which helps pull sweat away from your skin to keep you dry and comfortable during activities. The snug fit also helps reduce heat loss and prevents bunching, making it practical for wearing under both casual and formal clothes, or even as pajamas. The design focuses on comfort and minimizing skin irritation, which is important for all-day wear.

The fabric blend is soft and stretchy, though it might not offer the highest durability compared to some thicker or technical fabrics, so it may show wear over time with frequent use. This thermal underwear is a good choice if you want a lightweight, flexible, and warm base layer that fits well and manages moisture effectively. It suits women looking for comfort and warmth in cold weather, especially for layering under everyday clothing, though it may not be the best option if you need heavy-duty durability or advanced odor control.