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 Fruit of the Loom Men's 4-Pack Recycled Waffle Thermal Underwear Bottom offers solid insulation suitable for cold to moderately cold weather, thanks to its traditional full-length design and soft mini waffle fabric. The material blend of 52% cotton and 48% recycled polyester provides a comfortable feel with decent moisture-wicking and quick-drying properties, helping to keep you dry during activity. Its pull-on fit is straightforward and convenient for everyday wear. The reinforced flat seam construction adds to the durability, reducing the chance of discomfort or wear from friction.

This set is a good basic choice for those seeking affordable, comfortable thermal bottoms that balance warmth and breathability. It is especially appealing to customers who prefer environmentally friendly materials with recycled content.