10 Best Thermal Underwear Set 2026 in the United States

The Cuddl Duds Thermal Underwear Set for Women is a solid choice for those looking to stay warm in cold weather. Made from 93% polyester and 7% spandex, the material is both comfortable and stretchy, ensuring a snug fit. The brushed fleece inside and matte soft outside offer a cozy feel, while the spandex stretch provides ease of movement. This set is designed to be heavyweight, which means it can handle very cold conditions well. Its moisture-wicking fabric helps keep you dry by absorbing and evaporating sweat, which is a big plus for active wearers.

The set includes thoughtful design elements like thumbhole sleeves, modern rise leggings, and a tag-free label, which add to the comfort and practicality. Its sleek design makes it versatile enough to wear as a base layer or on its own, making it suitable for both outdoor activities and lounging at home. The protection from harmful UV rays is an added bonus, especially for those spending time outside.

Durability appears to be strong with densely knit fabric, but like any clothing, it will need proper care to maintain its quality over time. Machine washing is convenient, and the set's design and material make it a durable option. This thermal underwear set is ideal for women who need reliable warmth and comfort in cold weather without sacrificing style or mobility.

The Fruit of The Loom Men's Recycled Waffle Thermal Underwear Bottom is designed to provide warmth and comfort thanks to its soft waffle knit fabric made from a blend of cotton and recycled polyester. This mix helps trap body heat while feeling gentle on the skin. Its moisture-wicking ability is a strong point, as it pulls sweat away, keeping you dry during cold weather or active use.

The fit is snug yet flexible, allowing easy movement without feeling bulky, which is important for wearing layers or staying comfortable all day. The flat-lock seams help reduce skin irritation, and rib-knit cuffs at the ankles prevent the bottoms from riding up, which helps maintain warmth. An elastic waistband with a covered design ensures a secure and comfortable fit.

While the fabric blend supports durability, it might not be as long-lasting as heavier-duty thermal materials if used heavily outdoors. Also, there is no specific mention of odor resistance, so it might not perform as well in that area compared to some specialized options. This thermal bottom is a solid choice for everyday cold-weather layering, especially for those who want sustainable materials and reliable moisture control without extra bulk.

The Merino.tech Merino Wool Base Layer Set is a midweight thermal underwear set designed for men. This set includes a top, bottom, and a bonus pair of merino wool hiking socks, making it a comprehensive package. Made from 100% superfine 17.5-micron merino wool, it promises exceptional comfort without the itchiness that can accompany wool fabrics.

The material is notable for its moisture-wicking and odor-resistant properties, ensuring you stay dry and fresh even during extended wear. The breathability of merino wool helps regulate body temperature, making this set suitable for year-round use. However, the care instructions recommend hand washing and air drying for longevity, which may be less convenient for some users.

The set is imported and weighs one pound, making it reasonably lightweight. The fit is designed to avoid bunching and overheating, which adds to its comfort during daily wear. While the durability is not explicitly mentioned, the promise from Merino.tech to ensure customer satisfaction suggests a commitment to quality. This set would be ideal for individuals looking for comfortable, moisture-wicking thermal underwear with added benefits like odor resistance and temperature regulation, though the maintenance requirements may be a drawback for those seeking easier care options.