10 Best Pieces Of Thermal Underwear 2025 in the United States

The Cuddl Duds Thermal Underwear set is designed to keep women warm and comfortable in cold weather thanks to its brushed fleece lining and a smooth outer layer. Made from 93% polyester and 7% spandex, the fabric is lightweight (about 15 ounces) yet provides good warmth without bulk. Its spandex stretch offers flexibility and comfort for active movement, making it suitable for layering or casual wear. Moisture-wicking properties help manage sweat by drawing it away from the skin, which is great for maintaining dryness during outdoor activities. The set also features UV protection with a rating of 50+, adding extra shielding from the sun when worn outside. The thumbhole sleeves and tag-free labels focus on comfort and ease of use.

This thermal underwear is a solid choice for women who need a cozy, stretchy base layer for cold weather, especially for those who appreciate lightweight warmth with sun protection. It is less suited for heavy outdoor sports or activities that require strong odor control.

The Cuddl Duds Thermal Underwear for Women offers a cozy and practical base layer option for cold weather. It features a soft fleece lining inside for warmth and a smooth matte exterior, making it comfortable to wear both indoors and outside. Made of mostly polyester with some spandex, the fabric stretches nicely to allow easy movement without feeling tight or restrictive. It also has moisture-wicking abilities that help keep sweat away from your skin, which is important for staying dry during active use or layering. The outfit provides good sun protection with built-in UV defense, which is a beneficial extra not found in all thermals. The fit includes thoughtful details like thumbholes in the sleeves and a modern rise in the leggings for added comfort and style.

Weighing about 15 ounces, it balances warmth without feeling overly heavy or bulky, making it versatile as either a base layer or casual wear. If you want a soft, stretchy thermal set good for everyday cold weather needs with moisture control and UV protection, this set is a strong choice.

The Merino.tech Merino Wool Base Layer Mens Set stands out for its use of 100% superfine 17.5-micron merino wool, making it super soft and comfortable for all-day wear without causing itchiness. Available in midweight at 250 g/m², it strikes a balance between warmth and breathability, suitable for various weather conditions. The product also includes a pair of merino wool hiking socks, which is a nice bonus valued at $21.

This set is designed to regulate body temperature, keeping you comfortable throughout the year, and its natural moisture-wicking and odor-resistant properties ensure you stay dry and fresh during prolonged use. However, the care instructions recommend hand washing and air drying to maintain longevity, which might be inconvenient for some users. Additionally, while it offers good fit and comfort, it may not be ideal for those looking for heavyweight thermal underwear in extremely cold conditions.

Imported and machine washable, the set promises zero worries with a satisfaction guarantee from Merino.tech. It also comes in appealing packaging, making it a great gift option.