10 Best Cold Weather Thermal 2025 in the United States

WEERTI Thermal Underwear for Men is a solid choice for those looking to stay warm during cold weather. Made from a blend of polyester and spandex with a fleece lining, it offers good insulation by trapping body heat while remaining lightweight enough for comfortable all-day wear. The fit is snug like a second skin, which helps reduce heat loss and supports layering under various outfits, from casual to formal.

One of its strong points is moisture-wicking and breathability, as the fabric quickly moves sweat away to keep you dry and prevent that uncomfortable clammy feeling. The 4-way stretch material allows freedom of movement, making it suitable for active use without restricting comfort. Its seams appear durable, reducing the chance of early wear or tears. While the product description does not explicitly mention odor resistance, the synthetic fabric blend usually helps manage odors better than cotton.

On the downside, polyester-based fabrics can sometimes feel less soft against sensitive skin compared to natural fibers, and people who prefer natural materials might find it less breathable in extremely wet conditions. Also, since it’s imported and primarily polyester, it may not be the best choice for those seeking eco-friendly or purely natural fiber options. This thermal underwear serves as a practical and versatile base layer for men who want warmth, moisture control, and flexibility in cold climates.

The CL convallaria Base Layer set is designed to keep you warm and comfortable in cold weather, making it a solid choice for outdoor activities like hunting, skiing, or snowboarding. Made from a midweight fabric blend of 90% polyester and 10% spandex, it offers a cozy feel with added fleece for extra warmth. The midweight material strikes a good balance—not too bulky but warm enough for cold conditions. Thanks to four-way stretch, the fit is flexible and allows easy movement, which is great for active use. Moisture-wicking fibers help pull sweat away from the skin, keeping you dry and preventing that uncomfortable sticky feeling during extended wear.

The breathability is decent for a base layer, helping regulate temperature while providing insulation. Durability is supported by high-quality stitching that should hold up well through active use and multiple washes; the fabric is also resistant to pilling and shrinkage. The tagless design adds comfort, and the elastic waistband keeps the bottoms securely in place. Although the fabric blend offers good odor resistance, it may not be as strong as natural fibers like merino wool in this area. The care instructions recommend gentle washing to maintain quality.

This base layer set presents a practical and comfortable option for men needing reliable thermal underwear for winter sports or work, especially if synthetic fabrics are preferred and a product that moves well with the body is desired.

The Cuddl Duds Thermal Underwear set for women is designed to keep you warm and comfortable in cold weather thanks to its brushed fleece lining and heavyweight fabric. It’s made from a blend of polyester and spandex, which offers a good stretch for easy movement and a snug, flattering fit. The moisture-wicking fabric helps manage sweat by absorbing and evaporating it, which is great for staying dry during activities in chilly conditions. A nice bonus is the built-in protection from UV rays, making this set useful for outdoor use in winter sun.

The design includes thoughtful features like thumbholes and a tag-free label for added comfort throughout the day. The weight strikes a balance between warmth and avoiding bulk, so it can be worn alone or layered under outerwear. This set suits women who want a cozy, flexible thermal base layer for casual or active winter wear.

For those needing heavy-duty performance or advanced odor control, other options might be more suitable.