10 Best Thermal Ski Underwear 2025 in the United States

The WEERTI Thermal Underwear for Men is a solid choice for anyone needing warm and comfortable base layers in cold weather, including skiing or other outdoor winter activities. Made from a blend of polyester and spandex, it offers a soft fleece lining that feels gentle on the skin and keeps warmth locked in all day. The material is lightweight yet designed to be breathable, so it can wick away moisture and help keep you dry, which is important when you’re active and sweating.

The four-way stretch fabric provides a flexible fit without restriction or annoying bunching, allowing you to move freely whether you’re layering it under ski pants or wearing it alone as sleepwear. It also has odor-controlling properties, which is a nice bonus if you’re wearing it for extended periods. Since the fabric is mostly synthetic, it might not be as breathable as natural fibers like wool for very intense activities or in milder conditions.

This thermal set is practical and versatile, particularly suited for men looking for warmth, comfort, and easy care on cold days.

The Merino.tech Merino Wool Base Layer Women Set is a solid option for thermal ski underwear, particularly for those who prioritize comfort and performance in cold weather. The set includes a midweight top and bottom, made from 100% superfine 17.5 micron merino wool, which is renowned for its softness and comfort. The material is effective at regulating body temperature, making it suitable for a range of activities and conditions without causing overheating or discomfort.

Its natural moisture-wicking and odor-resistant properties help in keeping you dry and fresh during extended wear, which is valuable for skiing and other outdoor winter activities. The breathability of the material further enhances comfort by allowing heat to escape, preventing the buildup of sweat and moisture. However, the need for hand washing and air drying might be a drawback for some, as it requires extra care compared to more durable synthetic materials.

Additionally, while the product is designed for daily wear without rubbing or bunching, fit can be subjective and may vary from person to person. For those looking for a high-quality, comfortable, and functional thermal base layer, this Merino.tech set is an excellent choice, although the additional care requirements should be considered. The inclusion of a pair of merino wool hiking socks adds extra value to the package, making it a thoughtful gift for outdoor enthusiasts.

The Amazon Essentials Thermal Long Johns Underwear Set for Men is designed with a slim fit, contouring well to the body without excess bulk, which makes it suitable for layering under ski gear. Its fabric is a cotton-polyester blend (60% cotton, 40% polyester), offering softness and decent breathability thanks to the waffle knit pattern. This helps keep you comfortable by allowing some airflow, though it may not match synthetic-only base layers in moisture-wicking performance.

The set is lightweight, providing warmth without feeling heavy, making it suitable for cold conditions without restricting movement. The elastic waist and rib cuffs help maintain a snug fit, reducing drafts. It is reliable for everyday wear and priced affordably.

Casual skiers or those seeking comfortable, breathable, and warm base layers at a good value will find this set fits well, though those needing specialized moisture control or durability for intense skiing might look for more technical options.