The Best Thermal Underwear Kick Winter Where It Hurts

Long before the days of electric blankets (or electricity, period), the best thermal underwear was the only thing separating you from frostbite in the dead of winter. These days, the stakes might be a little less extreme, but in the darkest stretches of February, keeping your legs warm isn't as simple as just throwing on a pair of jeans. On those bone-chilling days, you need another layer underneath, one longer than your skivvies, and with a heckuva lot more heat retention. Think Kobe in his #8 era rocking full-length compression leggings, and you're on the right track.

Long underwear—a.k.a. long johns, a.k.a. thermal drawers—goes by many names, but there’s no confusion about what it does: serve as a protective barrier against winter's icy wrath. Below, we rounded up the absolute toastiest thermal undies on the market, from ultra-warm, performance-oriented riffs you can wear with PR-ready running shorts, to odor-resistant, next-gen versions you can sneak under your biggest office fits.

• The Best Thermal Underwear Overall: Uniqlo Heattech Ultra Warm Tights, $30
• The Best Budget Thermal Underwear: Indera Waffle Thermal Long Johns, $15
• The Best Upgrade Thermal Underwear: CDLP Merino Blend Long Johns, $95
• The Best Thermal Underwear for Getting Active: Lululemon Seamless Tights, $127
• The Best Era-Authentic Thermal Underwear: Hemen Ikar Long Johns, $65
• The Best Thermal Underwear for the Outdoors: Arc’teryx Rho Heavyweight Tights, $120

With Uniqlo, their bread and butter is literally building a wardrobe foundation for your entire fit game. From socks and beanies to underwear and T-shirts—and, of course, their coveted Heattech tights. If Nike has Dri-Fit, Uniqlo has Heattech, but trust me, theirs are way more dialed in. There are levels to this, for real: Regular (for mild cold), Extra Warm (for chillier temps), and Ultra Warm (for extreme cold).

Now, when we’re talking Ultra Warm tights, these aren’t just for looking cool. You can rock them under your shorts for an outdoor run or slip them under your snow pants while hitting the slopes. Soft, stretchy, and cozy? Absolutely. And the Ultra Warm version is 2.25 times warmer than their regular Heattech—so if you’re worried about being cold while layered up in these, don’t. There aren't too many thermal underwear options that act like a portable fireplace, wick away sweat, and still come in under $30. Another victory lap for Uniqlo, folks.

Each winter, you might as well stock up on these along with cold medicine and an industrial-sized box of tissues. Indera doesn’t just make top-tier waffle thermals—their matching tops are just as solid. And when a brand has been cranking out long johns for over a century, you know they’ve got the formula down.

Indera’s long underwear has that classic, no-nonsense look—the kind that pairs perfectly with some beat-up denim. At just 5 ounces, they’re great for temps hovering around 30 degrees and up, but if you’re braving anything colder, you’ll want something with a bit more heft. Ribbed cuffs and gussets make them comfortable and easy to pull on and off—because no one wants to wrestle with their thermals when it's freezing outside.

CDLP has built a reputation for making some of the finest underwear on the market, with their undershirts earning a near-cult following—because, apparently, once you try one, there's no going back. The Swedish label is like the luxury car of undergarments: sleek, modern, and engineered for peak performance (minus the sky-high maintenance costs). Naturally, their thermal underwear follows suit.

Made from a premium blend of Merino wool and lyocell, these long johns offer a silky-smooth feel—without the need for a silk budget. Merino wool keeps you cozy without turning you into a human sauna, and thanks to its natural antimicrobial properties, you can stretch out your wash day just a little longer (we won’t tell). The streamlined fit means no awkward bunching under your layers, so you can stay warm without resembling a walking marshmallow. In fact, these are some of the sexiest long johns ever—so if your current sleepwear consists of a questionably threadbare T-shirt and some mystery-fabric sweats, consider this your upgrade.

Understanding Lululemon’s fits is one thing, but the brand’s true north is comfort. The Vancouver-based label has already claimed prime real estate in closets everywhere for workout gear—and now, they’re making a play for what you wear underneath it, too.

Their latest base-layer bottoms are built from a performance-driven blend of nylon, Merino wool, and lyocell, making them durable, stretchy, and, most importantly, stink-resistant. (No one wants their post-workout musk lingering longer than their actual workout.) But the real kicker? They’re ergonomically designed for both support and room. And if you’re wondering why a word typically reserved for desk chairs is popping up in the world of long underwear, here’s the deal: these are shaped to follow your body’s natural contours, providing a snug-but-not-strangling fit that keeps everything in place without any awkward tightness. Sure, they come with a premium price tag, but when it comes to long underwear that actually fits your shape instead of feeling like a generic compression tube? That’s basically priceless.

These are the thermal underwear your favorite style icons would have worn—if they had any sense. The French undergarments label Hemen channels old-school craftsmanship so authentic you’d half-expect to find these in a 1940s military surplus catalog (right next to a tin of mystery rations).

Made from organic cotton with a 2x2 ribbed jersey knit. These long johns may look like they’ve time-traveled from decades past, but they deliver modern-day comfort. And those three front buttons? A vintage-inspired touch that’s not just for show—they make getting in (and, more importantly, out) of these thermals a breeze.

Arc’teryx somehow sits at the crossroads of “cool guy flex” and “serious outdoor gear,” and naturally, they’ve found a way to make thermal underwear look downright wearable on its own. Their heavyweight Polartec pants, feature patented Power Stretch fabric that moves with you—so you get warmth without the feeling of being shrink-wrapped.

The exterior is a soft, durable nylon, while the interior boasts a smooth brushed fleece that traps heat and wicks away moisture. And the best part? A small thigh pocket, perfect for stashing your lip balm or headphones while you’re catching your breath on the slopes (or just flexing at the après-ski lodge).

Long johns aren't really about making a statement, so colors and patterns don’t matter too much. What does matter, though, is fit and material. For maximum warmth retention, thermal undies should be snug but not overly restrictive. Oh, and flatlock seams are a must to prevent chafing; that should be non-negotiable.

When it comes to fabric, cotton is always a safe bet, but it absorbs moisture, which can actually make you colder. Synthetic blends—polyester, nylon, spandex—are quick-drying and durable, but have a bad habit of trapping odors. Merino wool, on the other hand is soft, moisture-wicking, naturally odor-resistant, and keeps you warm without adding bulk—and it's one of our go-to winter fabrics for those exact reasons.

Bottom line? Shimmying into a pair of thermal undies on a freezing day should feel like unlocking a level of toasty the lesser-equipped masses can only dream of.

Style is subjective, we know—that’s the fun of it. But we’re serious about helping our audience get dressed. Whether it’s the best white sneakers, the flyest affordable suits, or the need-to-know menswear drops of the week, GQ Recommends’ perspective is built on years of hands-on experience, an insider awareness of what’s in and what’s next, and a mission to find the best version of everything out there, at every price point.

Our staffers aren’t able to try on every single piece of clothing you read about on GQ.com (fashion moves fast these days), but we have an intimate knowledge of each brand’s strengths and know the hallmarks of quality clothing—from materials and sourcing, to craftsmanship, to sustainability efforts that aren’t just greenwashing. GQ Recommends heavily emphasizes our own editorial experience with those brands, how they make their clothes, and how those clothes have been reviewed by customers. Bottom line: GQ wouldn’t tell you to wear it if we wouldn’t.

We make every effort to cast as wide of a net as possible, with an eye on identifying the best options across three key categories: quality, fit, and price.

To kick off the process, we enlist the GQ Recommends braintrust to vote on our contenders. Some of the folks involved have worked in retail, slinging clothes to the masses; others have toiled for small-batch menswear labels; all spend way too much time thinking about what hangs in their closets.

We lean on that collective experience to guide our search, culling a mix of household names, indie favorites, and the artisanal imprints on the bleeding-edge of the genre. Then we narrow down the assortment to the picks that scored the highest across quality, fit, and price.

Across the majority of our buying guides, our team boasts firsthand experience with the bulk of our selects, but a handful are totally new to us. So after several months of intense debate, we tally the votes, collate the anecdotal evidence, and emerge with a list of what we believe to be the absolute best of the category right now, from the tried-and-true stalwarts to the modern disruptors, the affordable beaters to the wildly expensive (but wildly worth-it) designer riffs.

Whatever your preferences, whatever your style, there's bound to be a superlative version on this list for you. (Read more about GQ's testing process here.)