Style: Aesthetics don't much come into play, but just like when we're reviewing underwear, we still expect there to be a flattering fit and thoughtful details.
Comfort: You're wearing long underwear against your skin for hours, sometimes all day. So no matter the fabric, we wanted it to be soft and gentle, without snagging or bunching.
The Best Affordable Long Underwear: Uniqlo Heattech
Like Google or Kleenex, Uniqlo’s Heattech is basically a synonym for the larger world of thermal underwear. As in, Oh, it’s going to be 20 below before windchill today? That’s Heattech weather. Or, Your Quebec ski trip is this weekend? Better stock up on Heattech.
That synonymy is well-earned: the stuff is warm, easy on the skin, and affordable enough to buy in bulk. These days, Uniqlo makes three levels of Heatteach gear: regular, Extra Warm, and Ultra Warm. We’re fans of the middle option. It has a brushed texture inside and a tee-shirt-like weight that's toasty but still breathable enough that you won’t sweat bullets indoors.
Because it's majority cotton, Uniqlo's Extra Warm layers aren't particularly sweat-wicking. Human furnaces or anyone with sporting intentions should stick to the Uniqlo's basic, lighter synthetic-blend set—or scroll down for more options.
The Best Long Underwear for Hitting the Slopes: Icebreaker
If you’re planning on spending time on a mountain this winter—whether that means hiking up or skiing down—Icebreaker's set is what you want. Neither half is cheap, but that's because they're made from merino wool, which naturally ward off odors, wicks away moisture, and regulates your body temperature. (Turns out sheep are innovators.)
If you're worried about wearing that much wool against your skin, don't: part of the price is the high-end, ultra-soft merino that Icebreaker uses, joined with flatlock seams to sidestep any chafing.
Oh, also: Icebreaker's base layers machine washable, and though they can't go into the dryer, they air dry extremely fast. Which is to say, you probably only need one pair for a long ski weekend: two if you're swapping between your mountain set and your hitting-the-town set.
The Sleek Cotton Long Underwear: CDLP
CDLP makes some of our favorite underwear, partly because it somehow weaves a little sex appeal into men's drawers. And partly because the brand's go-to fabric, a mix of lyocell and cotton, just feels so cool and sleek on the skin. Which, now that we think about it, may be part of the sexiness.
And while there's absolutely nothing sexy about listening to Alexa talk about wind chill as you're getting ready for the day, we can say that CDLP's lyocell-cotton blend thermals feel silky without the price of silk (more on that below).
The Most Luxurious Thermal Underwear: Hanro
On the most brutal winter days, when you wake up feeling extra gloomy, keep this set by the bed so you can at least keep the chill from sapping all of your motivation. Thanks to an opulent blend of merino and silk, Hanro's thermals are deceptively light and airy, feeling like absolute heaven against your body while still packing in the heat. Dropping more than $300 on undies—sold on Amazon, no less!—might seem crazy, but suffering through months of torture is worse. Treat yourself. You deserve it.
The Best Long Underwear for Training: Lululemon
Lululemon
Engineered Warmth Long-Sleeve Crew
If your idea of cold-weather activities involves a blood-rushing assortment of winter sports or staying on your spring marathon training program, let us direct you to Lululemon’s Keep the Heat Thermal Tight.
The mix of wool and synthetics makes for an odor-resistant set that's well equipped to keep your body heat comfortable (as in, warm when you're starting out, but never overheating when you're hitting the higher heartrate bpms). And because they're tights, and as likely to be worn with shorts (or maybe nothing at all, if you like to exercise light-n-free), they're a bit more wind-resistant than your average thermals.
Lululemon's matching “Keep the Heat” top has been discontinued, and the next closest (read: tightest) base layer the brand still has in stock is on final sale with limited sizing. So we’ve recommend the Engineered Warmth long sleeve crew, which is more of a crewneck, but would work under a jacket or vest for running or exercising .
The Best Long Underwear for Sleeping: Abercrombie & Fitch
Abercrombie's set borrows the waffle-y goodness of old-school thermals and channels it into loungewear. No, you're not layering these under anything—except maybe your sheets. Some polyester in the mix helps wick sweat and keep the fabric a little lighter-feeling, making them great for cool sleepers who don't want to pile on a second comforter (maybe because your partner won't let you). And they'll rise to “best pajamas” status for anyone who wants to pad around the house—or that ski-in, ski-out Airbnb—in warmth and softness while nursing a cup or three of coffee.
14 More Pairs of Thermal Underwear We Like
Smartwool's performance-minded leggings may use an age-old fiber to get the job done, but it's the innovative blend behind it that really heats things up. They combine soft merino wool and stretchy nylon for a calculated combination of insulation and movement, a custom fit for warmth and durability.
When it reaches a cold so cold that even your trusty North Face Nuptse puffer can't fully cut, slip on this moisture-wicking set to keep your inner fire burning.
When you imagine long underwear, these are probably what you picture first: heavy ribbed, button-fly henleys and long johns in heather gray and white. French luxury underwear brand Hemen took that concept and somehow made it sexy. Made in Portugal from plush GOTS-certified organic cotton, this pre-washed (to avoid shrinkage), hardily-constructed set is as traditional and cozy as can be—but it hugs in all the right places.
Not all merino is the same. This set features an ultra fine knit that keep your warm while wicking away sweat and providing SPF protection (because the sun is still shining even in the winter). Even better, they're machine-washable.
You'll be feeling like a real magician, smoothly dodging the cold in this sleek as hell, 100% merino set.
If declining temps are your bird call to engage in adrenaline-pumping outdoor activities, this lightweight, naturally temp-regulating wool set will make sure you stay warm and dry no matter what you're climbing.
No tags, barely any seams, and a specially-designed waistband that won't dig in or bunch up throughout the day.
If your idea of a winter workout is a skiing in Vail, these ultra-luxe, insanely soft merino long johns deserve pride of place in your weekend bag.
Mack Weldon's micro-waffle knit fabric is as hearty as the cold-weather breakfast food that inspired its name—and a whole lot nicer to slip beneath your work pants.
Moisture-wicking long johns with just the right amount of stretch, for a very nice price.
Like a little wiggle room around your nether regions? L.L.Bean's long underwear is made out of two layers of super-soft Lycra, to prevent bunching.
If you're worried about your gut expanding unduly over the course of a months-long hibernation on the couch, an elastic waistband—coupled with a soft, stretchy fabric for added flexibility—is the way to go.
Billed as Patagonia's "most advanced" base layer ever, this synthetic Capilene Air duo traps warmth, dries swiftly, and keeps odors at bay even on multi-day camping trips.
If you need something thin, try this set. It's made from modal, a cotton-like fabric fashioned from beech trees that's sleek, strong, and smooth, almost like silk.
