The Best Thermal Underwear for Men, Tested by Style Editors

Among the thermal underwear we gave a test drive, Thermajohn managed to leave the best lasting impression on us, thanks to its smart design and high-performance features. For starters, the fabric is engineered to trap body heat, which will keep you toasty in sub-zero temps during the winter. You can expect this to come in handy especially if you’ll be shoveling snow, skiing in the mountains, or skating on ice with your partner. Also, the polyester/spandex blend has a stretchy, body-hugging feel that doesn’t restrict any natural kind of movements.

Another highlight is the fleece-lining that provides optimal warmth and feels amazing against your skin. To top it off, it’s moisture-wicking too, thus making them easy to wear for all types of adventures. After all, nobody wants to feel clammy when they’re bundled up. We found that it’s perfect for layering anything from jeans and sweaters to ski pants because of its slim profile.

Read More: Best Underwear for Men

If you ask us, there’s nothing better than a pair of thermal underwear that moves when you move. The REI Co-op Midweight base layer bottoms are ideal for our active guys who are constantly outdoors or engaging in some sort of sport. They’re made with recycled materials and four-way stretch for extreme comfort.

We love the smooth surface on our skin and the brushed back that provides added warmth in colder temperatures. We’re talking zero itch and a long lifespan. A nice touch is the UPF 50+ rating that protects against sun rays. Plus, the fabric wicks away moisture and has low-bulks seams for easy layering in the winter season.

Shop the Matching Top: Midweight Long-Sleeve Base Layer Top

It’s always a win-win when you can get thermal underwear, both tops and bottoms at a budget-friendly price. Take this set from 32 degrees, which consists of a soft, lightweight four-way stretch fabric that includes moisture-wicking and quick-0dry technology, keeping you warm without overheating.

We found it’s equally functional as loungewear, gym gear or as everyday base layer pants. During our testing, our editors wore them underneath their best sweatsuits and the pair didn’t compromise on breathability or mobility. Despite its price tag, these base layers hold up well to repeated washing and wear.

Shop the Matching Top: Performance Lightweight Thermal Base Layer Crewneck

Attention campers, climbers, cyclists: Winter is full effect and Finisterre has the secret weapon for your favorite outdoor sports. Enter the Eddy 2.0 Merino Wool Long Johns. They’re basically a warm hug that’ll prevent you from freezing your butt off. Not only are these thermals super breathable, but they’re also naturally antibacterial, so you can wear them days at a time without worrying about funky smells (believe it or not).

It’s a go-to for our Gear Editor, Ryan Brower who prefers a pair that’s not skin-tight and doesn’t constrict your movements. Unlike the other base layers that hug your body closely, this option isn’t as clingy, but still fits comfortably underneath a pair of chinos or jeans. Another thing to note: The Merino wool feels ridiculously soft against the skin, compared to traditional wool that has thicker, coarse wool fibers causing one to itch.

If you want a form-fitting choice that skims the body but allows for movement and comfort as you hit the weights, check out Under Armour’s HeatGear Leggings. This option is designed to keep you cool and dry during those intense workouts in warm or moderate conditions. While you’ll find that the pair wicks away moisture and helps regulate body temperature, it doesn’t provide complete warmth like the others we’ve tested. No, you won’t go shivering. But it focuses on breathability and moisture-wicking rather than heat retention—which are still essential for daily gym-goers.

These leggings can be used for activewear or as base layers, depending on the activity or environment. Thanks to the elastane, we didn’t feel restricted with any bending, lifting, or stretching. And as you’re on the move, you can secure your phone with the drop-in pocket on the hip.

Shop the Matching Top: HeatGear Compression Long-Sleeve T-Shirt

Founded in 2011, the menswear brand Mack Weldon, which develops its own fabrics, has quickly climbed the ranks as a top purveyor of men’s basics, with its thermal underwear no exception. Case in point: The brand’s warmknit fabric constructed in a micro-waffle knit and featuring their insulating Thermolite technology makes for a great base layer that keeps the temps just right. We love to lounge in this pair on the weekends with nothing on our plate besides Netflix binging on the couch. It’s super lightweight and feels extra comfy to even sleep in.

Shop the Matching Top: Warmknit Waffle Henley

Taking pride in its Merino wool items developed for the outdoors, Meriwool’s base layer thermal pants provide more than enough warmth without any of the claustrophobic stuffiness. Thanks to the underwear’s 100% Merino wool interlock knit fabric construction (with this pair being the brand’s heaviest weight), sweat is wicked away and odors kept at bay without you losing any heat.

Compared to any other option, we found this option leans more on the heavy side, which is ideal for nearly unbearable climates. With 400g of warmth, these pants will bring the heat for all cold-weather activities such as cross country skiing, sledding, or tubing.

Shop the Matching Top: Meriwool Base Layer Thermal Shirt

Whether you’re a construction worker, firefighter, or landscaper, Carhartt has the best pair of thermal underwear for you. Designed with rugged flex technology, this option helps increase mobility and durability for physically demanding outdoor jobs. The waffle knit fabric does does an exceptional job at fulfilling all your needs: Trapping heat, tackling odor, and managing moisture through its swift-drying and sweat-wicking elements.

Our editors found that its rugged flex tech makes moving around a breeze, with the added benefits of tactically placed seams reducing chafing and improving comfort. Aside from outdoor workers, this pair layers perfectly under performance gear for winter sports.

Shop the Matching Top: Base Force Midweight Classic Crew

Lululemon’s seamless design is hands down the best lightweight option we’ve tried out the bunch. With this pair, there’s no annoying seams digging into your skin, and it feels smooth and barely there—like second skin. Unlike others on this list, these tights have a unique blend of nylon, Merino wool, lyocell and elastane. In other words, it combines the best features of these materials to offer comfort, performance and natural warmth.

During our trial, we worn these during morning jogs in brisk temperatures, snowy hikes and on long-haul flights that tend to get chilly. In addition to being itch-free, the pair incorporates an ergonomic pouch with sufficient space to support your nether regions. And they’re not too shabby enough that you can’t wear it underneath your gym shorts, whether you’re hitting the grocery store or clocking in those miles.

Shop the Matching Top: Seamless Base Layer Long-Sleeve Shirt

You know what’s superior than a pair of waffle long johns? Three pairs of waffle long johns. We’re big fans of the multi-pack from Fruit of the Loom that gives you the ability to cycle through your thermal underwear for multiple days of wear. That’s perfect if you’re wearing them for work or simply wanting to wait longer to do laundry.

The bundle doesn’t comprise of the fanciest or most high-tech thermal underwear out there, but what you receive still gets the job done. In fact, we found that the trio has a solid amount, if not equal, comfort and protection as of those that are made with new and improved fabric blends. Plus, you don’t have to dish out a fortune to have similar quality.

Shop the Matching Top: Recycled Waffle Thermal Underwear Henley Top

Midweight thermal layers are ideal for moderate to cold weather, striking a solid balance of warmth and flexibility. Enter Patagonia’s Capilene base layer. It’s produced with a comfortable elastic waist and a diamond-grid pattern, which creates air pockets that cage body heat, improves breathability, and works to channel sweat away from your skin to the fabric’s surface.

Based on our extensive testing, we found it’s more thicker than Lululemon’s version without feeling too heavyweight. Comfort is also a priority, as the seamless 3-D construction reduces chaffing while the front crotch’s double layer adds extra support to your package.

Shop the Matching Top: Capilene Midweight Crew Top

What’s the Difference Between Base Layers and Thermal Underwear?

Base layers and thermals are designed for different intended uses. While both are worn as an undergarment, base layers are a second skin that can add considerable warmth, wick away sweat, and regulate body temperature. Whereas thermal underwear work to retain heat and keep you cozy. Typically, you wear them alone or under a sweater or pants—indoors or out.