10 Best Thermal Long Johns 2025 in the United States

The WEERTI Thermal Underwear for Men Long Johns is designed to be a reliable base layer for cold weather. Made from 92% polyester and 8% spandex, the material is lightweight yet offers warmth and comfort. The fleece lining helps in trapping body heat, making it suitable for layering under various types of clothing, from formal wear to casual outfits. The snug fit mimics a second skin, minimizing heat loss, while the 4-way stretch fabric ensures full mobility and flexibility without tearing the seams prematurely.

This is ideal for those who need comfortable yet durable thermal wear for both outdoor activities and lounging at home. The moisture-wicking feature is a significant advantage, keeping sweat at bay and maintaining dryness throughout the day, which is essential for staying comfortable in cold conditions. Additionally, the fabric's odor resistance helps in maintaining freshness after extended wear. However, a potential drawback is the polyester blend, which might not be as breathable as natural fibers like wool. Also, the fit being snug may not be suitable for everyone, particularly those who prefer a looser fit.

Nonetheless, these long johns offer a good balance of warmth, comfort, and functionality for cold weather use.

The Cuddl Duds Thermal Underwear set offers a cozy and practical option for women looking to stay warm in cold weather. Made from a polyester and spandex blend, it features a soft, brushed fleece interior that provides warmth without feeling bulky. The spandex content gives the top and leggings a comfortable stretch, making it easy to move around or layer under other clothing.

This set is designed to wick moisture away from your skin, helping to keep you dry during physical activity or throughout the day. It also offers added UV protection, which is a nice bonus if you spend time outdoors. The seamless design with a tag-free label and thumbholes in the sleeves adds to comfort by reducing irritation. Weighing just under 15 ounces, it’s lightweight enough to wear for extended periods without feeling heavy.

It is suitable as a base layer or worn on its own indoors, meeting the needs of anyone seeking warm, stretchy, moisture-managing thermal wear for everyday winter use.

The Fruit of The Loom Men’s Recycled Waffle Thermal Underwear Set offers a solid balance of warmth, comfort, and practicality for everyday cold weather use. Its blend of 52% cotton and 48% recycled polyester creates a soft waffle knit fabric that traps heat effectively without feeling bulky. This makes it suitable for moderately cold conditions and layering under other clothes.

The set features a fitted design that hugs the body snugly, which helps keep warmth in and reduces excess fabric, making movement easier. Moisture-wicking dual defense technology is included, which means it pulls sweat away from your skin to keep you dry and fresh through the day — a key feature if you plan to wear it during physical activities or for long hours. The flat-lock seams and tag-free neck design enhance comfort by minimizing irritation and chafing, which is important for sensitive skin or extended wear. Ribbed cuffs at the wrists help keep the sleeves in place and seal in warmth.

There is no specific mention of odor resistance beyond moisture control, so if that is a priority, you might want to consider other options with antimicrobial treatments. This set works well in cold conditions, but it may not be the best choice for extremely harsh winters or very high-intensity outdoor activities that require heavier insulation or specialized fabrics. This thermal underwear set represents a dependable, comfortable choice for everyday winter wear and layering, especially if you appreciate eco-friendly materials and good moisture management.