The 19 Best Pairs of Thermal Underwear for Men

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Whether you live north of the Wall or you’re a sweet summer child, we can probably sum up your reason for seeking out the best thermal underwear for men in just three words:

Winter is coming.

You just know this guy’s wearing long johns – or should I say long “Jons”? (Actually, I guess it’s “long Aegons”?)
Image via HBO

Men’s thermal underwear and long johns can help you maintain body heat during outdoor activities, or just stay snuggly and cozy while bumming around your condo.

And while keeping your body temperature comfortable in a cold climate is certainly important, we’d be remiss if we failed to point out another advantage:

The right pair of long underwear can actually look pretty cool (no pun intended), and in the opinion of some women, even downright sexy.

That’s why we’ve rounded up the best fitting, warmest and highest quality long johns available online, and included a few insights from Amazon users who have put each pair to the test.

Read on to find our comprehensive list of the best thermal underwear for men who want to stay warm this winter.

The Best Thermal Underwear for Men

Breaking Down the Best Long Underwear for Men
Overall Best Pair of Men’s Thermal Underwear ↓

Meriwool Men’s Merino Wool Base Layer  

Meriwool Merino wool thermal pants
  • 4.9 Stars on Amazon
  • 50 ratings
  • 100% Merino wool

Using a synthetic material like nylon makes sense for men’s gym clothes, which are designed to let heat escape and keep you cool.

But when it comes to thermal underwear, the best base layer comes in the form of warm, breathable and natural merino wool, which is what makes this pair from Meriwool so great.

These long johns are made from 100 percent, all-natural, superfine 18.5-micron, merino wool, which means they are super comfortable and highly breathable, with none of the itchiness that can come from other thermal underwear fabrics.

As a bonus, merino wool also provides a natural odor-resistance that helps ward off the – how should we put this? – less than desirable scents that sometimes accumulate down south after you seal your boys into a tight pair of long johns all day.

Promising Review: “Very comfortable wool bottom layer! I bought this as a base layer in my scuba diving drysuit since wool is a great insulator, even when it gets wet! I’ll be using this under my snowboard gear as well, and for other cooler outdoor activities!!” – Will

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The Best Men’s Thermal Underwear Bottoms

Duofold Men’s Midweight Double-Layer Thermal Pant

Duofold Men's Midweight Double-Layer Thermal Pant
  • 4.6 Stars on Amazon
    • 2,353 ratings
  • Inside Layer: 100% Cotton; Outer Layer: 65% Cotton, 25% Merino Wool, 10% Nylon

Duofold’s Midweight Double-Layer Thermal Pant is the company’s warmest pair of thermal pants for men, making them great for extreme cold temperatures. 

Using what the brand calls dual-layer technology, the inner layer consists of 100% cotton, with an outer layer of merino wool and nylon, giving you plenty of protection on a particularly cold day. 

The flatlock seams also mean the pants are durable (even during long days) and will cut down on chafing, regardless of the activity you use them for.

Promising Review: “Can’t tell you enough how they are exactly what I wanted. I am 200 lbs 5.11 size 44 pants, took 2X, they fit perfectly, not cold anymore !! To sleep I need to be warm, even the house is 72 degrees I am cold. I sleep with them to get a good night’s sleep. I am purchasing more.” – S.B.G

Indera Men’s Icetex

Indera Men's Icetex
  • 4.3 Stars on Amazon
    • 439 ratings.
  • 100% Cotton Outside 100% Polyester

After more than 100 years making thermal underwear, it’s safe to assume Indera knows what it’s doing. 

The Indera Men’s Icetex is made with a heavyweight cotton raschel knit on the outside and polyester fleece on the inside for added warmth. 

This allows it to provide heavyweight warmth, while still feeling like a lightweight second skin on your body.

Promising Review: “The order came on time so I could wear the nice and warm underwear. The weather is changing so I needed something warm and lightweight. These were exactly what I needed. They keep you warm without being heavy. Kept warm all day. Will be buying another pair soon.” – James Kozak

Carhartt Men’s Force Midweight Classic Thermal Base Layer Pant

Carhartt Men's Force Midweight Classic Thermal Base Layer Pant
  • 4.6 Stars on Amazon
    • 4,106 ratings
  • 100% Polyester

Sometimes, the best underwear is the most simple.

That’s exactly what this pair of Carhartt thermal pants is: a tough, basic option made with rugged flex technology. 

The synthetic fabrics allow it to fit you very well, and let you move easily while out there in cold conditions.

Promising Review: “This base layer has been a godsend for me! It fits snug, yet not tight at all. It is flexible enough to wear compression shorts and thicker socks underneath. The extra space leaves enough room, so that I don’t feel uncomfortable in my groin area. It’s kept me extremely warm.” – D. Jones

Terramar Men’s Thermasilk Pant

Terramar Men's Thermasilk Pant
  • 4.4 Stars on Amazon
    • 1,003 ratings
  • 100% Silk

There’s something about these silk long johns that just screams warmth. And thankfully, these Thermasilk pants by Terramar will keep you warm – like really really warm.

Created originally with military personnel in mind, this piece holds up on the insulation – even in the direst of situations. 

The base layer bottoms use what Terramar calls their Climasense technology, which allows them to control your skin’s temperature so you don’t overheat.

Promising Review: “The silk pants are so comfortable that I cannot feel like I am wearing long underwear. And as silky as they are, they are warm to wear in our Washington winters. I highly recommend these Terramar pants for anyone who needs warm but light clothing and are great for outdoor activities in the winter.” – Piranha6

Fruit of the Loom Men’s Classic Midweight Waffle Thermal Underwear Bottoms

Fruit of the Loom Men's Classic Midweight Waffle Thermal Underwear Bottoms
  • 4.4 Stars on Amazon
    • 19,428 ratings
  • 65% Polyester, 35% Cotton

This casual base layer is super for feeling cozy around your apartment, and easy to wear under your pants when the temperature drops and you’re going out to run errands or perform other everyday activities. 

If you live or work in extreme cold weather, you might want to opt for one of the wool base layers on this list, which provide a little extra warmth.

But for most of us, this is a great go-to option that offers a comfortable fit for all body types. 

Promising Review: “Purchased for husband. Fits as expected. Soft, washes and dries nicely. A good value. Glad we could buy bottoms separately from tops (would need a larger top than bottom.) These fit the same as ones from many years ago. Gray looks so much nicer than cream-colored ones.” – Brenda Castillo

Best Thin Thermal Underwear for Men ↓

2UNDR Men’s Long John 

2UNDR Men's Long John
  • 4.8 Stars on Amazon
    • 48 ratings
  • 100% Cotton

Let’s cut to the chase: if you’re the type of guy that experiences more chafing down there, then this pair of 2UNDER long johns is for you.

The thermal underwear is made with a chafe-free flat-lock seam construction, which is designed with your most prized possessions in mind. 

So you can say bye to chafing, and the need to be constantly adjusting yourself down there.

Promising Review: “I wore these under my snowboard pants, perfect fit, stretchy around the twins area, and overall kept me warm and flexible, which is exactly what I was hoping for. Do yourself a favor and just buy these for cold weather, they feel like you’re freeballing it without the stick to the walls feeling (guys know what I mean).” – Chris

Minus33 Merino Wool 706

Minus33 Merino Wool 706
  • 4.7 Stars on Amazon
    • 1,358 ratings
  • 100% Merino Wool

Doing the right thing to keep you warm and to save the planet, Minus33 uses a type of fabric that leaves low environmental footprints: merino wool. 

(Editor’s Note: Comfortable, warm, and good for the environment? More like mer-agical wool, amirite? I’ll show myself out…)   

Packed with wool fiber that is 18.5 microns wide, this makes it wearable against the skin and absorbs moisture so you don’t feel wet. 

Plus, it’s UV protected so you can wear it outdoors while camping on a sunny day without fear.

Promising Review: “This winter has been COLD in upper Iowa. So I decided to try a new type (for me) of Long Johns… No more burning skin and waffle marks from sitting after coming inside. No more sweaty parts after being inside for awhile… These are comfy!!!”Terry Moody

ARCITON Men’s Long Johns 

ARCITON Men's Long Johns
  • 4.4 stars on Amazon
    • 591 ratings
  • 95% Cotton, 5% Spandex

Who said Thermal Underwears have to be boring? 

ARCITON’s Long Johns aren’t just underwear, they’re a fashion piece. 

Some underwear brands primarily focus on comfort, while others offer a range of different colors and fun patterns, but this pair manages to do both. 

And thanks to its blend of materials (95% cotton and 5% Spandex), they’ll keep you both comfy and warm in equal measure.

Promising Review: “I love these so comfy and fit great. I bought the value pack so I can have a variety. I’ve had other brand that was all cotton and those I’d sweat in these are spandex and little cotton breathe better and definitely shows an outline and enhances your butt a bit. Would definitely recommend these” – Badass

Icebreaker Merino Men’s 260

Icebreaker Merino Men's 260
  • 4.6 stars on Amazon
    • 39 ratings
  • 100% Merino Wool

If you don’t have the blood of House Stark coursing through your veins (or those rugged as hell furs they drape around their shoulders), Icebreaker’s merino 260 long johns are warm enough to keep you from freezing when you venture north of the wall. 

This base layer is engineered to keep you warm and designed with a gusset for added comfort on the move. 

So whether you climb a mountain, a ski slope, or the wall while undercover with the Wildings (sexy redheads will make guys do all sorts of crazy things), you are good to go.

Promising Review: “Fits great, keeps cold out and light weight” – Kevin Nimmo

32 DEGREES Men’s Thermal Baselayer Pant

32 DEGREES Men’s Thermal Baselayer Pant
  • 4.7 stars on Amazon
    • 721 ratings
  • 37% acrylic, 34% polyester, 25% rayon, 4% spandex

The 32 Degrees Lightweight Baselayer pant is another inexpensive pair made of varying mixes of polyester, acrylic, rayon, and spandex that are extremely comfortable.

So if you are looking to give outdoor activities a try in the cold season and don’t want to break the bank, go 32 Degrees (pun intended)

Promising Review: “I bought these for my husband to wear on cold mornings and he likes them very much. They fit well and keep him warm. The material is silky feeling so they don’t bind up on cotton scrubs or cause static electricity. The price for the 2-pack is fantastic – less expensive then anywhere I’ve found.” Kimmi

The Best Thermal Shirts for Men

Overall Best Mens Thermal Shirt

Smartwool Men’s 250 Baselayer Crew Slim Fit Shirt 

Smartwool Men's 250 Baselayer Crew Slim Fit Shirt
  • 4.9 Stars on Amazon
    • 164 ratings
  • 100% Merino wool

Before you go on to tackle the winter weather, do yourself a favor and get the Smartwool Merino 250 top. 

It’s 100 percent merino wool with interlock knit, making it significantly durable.

And despite the durability, it remains soft and comfortable enough for whatever activity you want to take it through. Not to forget that the seams are flat locked, so it’s sure to last you a long time.

There are several color options for this baselayer shirt, but can you ever go wrong with black?

Promising Review: “I despise having to take these off to wash them, which according to the manufacturer you don’t have to do that often. I would recommend them to anyone.” – Jay K.

Best Fashion Thermal Underwear for Men ↓

Under Armour Men’s ColdGear 

Under Armour Men's ColdGear
  • 4.7 Stars on Amazon
    • 9,889 ratings
  • 87% Polyester, 13% Elastane

As one of the few brands big enough to compete with Nike, Under Armour needs little or no introduction when it comes to making apparel. 

The Coldgear long sleeve comes with a smooth interior and exterior that leaves you comfortable. 

It also adds some design flair to the humble long sleeve and gives it this amazing look that is somewhat difficult to look at just once. 

Time to turn some heads while you make that run. (You can thank me later.)

Promising Review: “Awesome base layer. I use this as a base layer for cross country skiing. I wear this and one more layer over it. I’m not sure if it’s the shirt or the activity but I’m pretty warm using it.” – Menoc

ColdPruf Men’s Basic Dual Layer

ColdPruf Men's Basic Dual Layer
  • 4.5 stars on Amazon
    • 1,701 ratings
  • 60% Combed Cotton, 40% Polyester

At a great entry-level price, this thermal underwear top from ColdPruf is a solid option for those who want to get their money’s worth.

It’s made up of cotton and polyester both combined to feel like one and smooth. Comfort at an affordable price? Get me you a Coldpruf already.

Promising Review: “Needed the shirt to go snowmobiling in upper peninsula in Michigan. Below zero weather. Short was warm, lightweight, and soft. Glad I had it.” CraigF

FitExtreme MaxHeat Mens Thermal Underwear

FitExtreme MaxHeat Mens Thermal Underwear
  • 4.4 stars on Amazon
    • 236 ratings
  • 92% Polyester, 8% Polyurethane

This is premium, silky soft fleece thermal provides excellent comfort and warmth in cold weather. 

The synthetic materials it is made with allows for tons of movement, as it stretches and clings to your body.

It also sports a classy design with blue stripes. It comes in four varieties, but the Navy blue option does it for me.

Promising Review: “Warm and cheap! I’ve been wearing this brand for a few years now. They’re much thicker than my sets of Columbia thermals.”Mark G

The Best Men’s Thermal Underwear Sets

Overall Best Thermal Underwear Set for Men ↓

TSLA Thermal Underwear Set 

TSLA Thermal Underwear Set
  • 4.5 Stars on Amazon
    • 9,735 ratings
  • 92% Ultra-Soft Microfiber, 8% Spandex

A great choice for those cold mornings when you’re outdoors – jogging, hiking, skiing, you name it – TSLA’s thermal underwear is perfect for the guy on the go during winter months.  

This thermal set wicks moisture on both the top and bottom, keeping you less sweaty, and also packed with a 4-way stretch that keeps you warm without slowing you down.

Promising Review: “Nice warm base layer. Just took a walk in 25° calm weather and felt nice and comfortable the whole walk(about 20 min outside). The material is suuuuper stretchy and hugs your whole body. Now I’m inside and just wearing it as a shirt and not sweating to death. The material really breathes well and I’ll be more than happy to buy 2 more pairs. 5 star guys, awesome job” – Justin

LAPASA Men’s Heavyweight Thermal Underwear

LAPASA Men's Heavyweight Thermal Underwear
  • 4.6 stars on Amazon
    • 3,492 ratings
  • 95% Polyester, 5% Spandex

Another entry in the thermal underwear sets, LAPASA deserves inclusion here thanks to its heavyweight fleece-lined long johns.

This particular set is built for winter, thanks to it being 1.6 times the weight of lightweight underwear. 

Another unique feature is that despite its weight, it supports movement because of its draping tailoring, which provides an excellent body fit.

Promising Review: ”I can stand outside in these 5 degrees F and not even feel the cold on my body. Not sweating or uncomfortable, just a nice warm disbelief that these work so well… I LOVE THESE THERMALS SOOOOOO MUCH, I could keep going on about em but you get the point.”HiSeaLuBooGrace

Thermajohn Men’s Ultra Soft Thermal Underwear

Thermajohn Men's Ultra Soft Thermal Underwear
  • 4.6 Stars on Amazon
    • 23,287 ratings
  • 92% polyester, 8% Spandex

There’s a reason Thermajohn’s Thermal Underwear is prominent among many users; they are some of the most comfortable pieces you can find.

This thermal underwear is moisture-wicking and lightweight – so much that you might even forget that you have them on thanks to the poly-spandex fabric it is made with.

Promising Review: “I bought these for my hubby because he works out in the elements and he had been talking about how he only had one pair of thermals under his clothes. These were perfect! They fit nicely and are very soft. They are not like your regular thermals. They are smooth and fit well under his work clothes. I will definitely be buying more.” – Amy

HEROBIKER Men’s Thermal Underwear Set

HEROBIKER Men’s Thermal Underwear Set
  • 4.6 stars on Amazon
    • 8,033 ratings
  • 92% Microfiber, 8% Spandex

This performance-ready set features ventilation and warmth for all-day utility. 

The wool material it’s made from also ensures that it’s lightweight and comfortable enough to be worn under other clothes, or alone as outdoor wear.

As one of the reviews said, it is “cozy and not restricting at all.”

But one note: Amazon reviews suggest that these run small, so you’ll want to size up when ordering.

Promising Review: “These are great – my husband loves them. They are definitely small and per other reviews I ordered a size large even though my husband usually wears a medium and the fit is perfect. They are warm and tight and will definitely do the job. He says they feel very cozy and not restricting at all. The material seems durable and high-quality.” Daley M

You Know the Best Mens Thermal Underwear 

Now learn how to make your outer layer look even better

Now that you know which pieces constitute the best rated mens thermal underwear, you’ll be able to keep warm and layer up in comfort.

But let’s be honest: while the right pair of long johns is essential for staying warm in cold climates, even the best extra layer won’t really help you look sharp when it’s buried underneath your clothes.

To stand out from the (fully clothed) crowd, you need to know how to optimize all the layers that go on top of your long johns by mastering the small but important details that make a big difference on the way you look.

We’ve put together a head-to-toe checklist that will help you do just that. It outlines the nine details you need to nail if you want to look your best, and walks you through how to implement each one so you can optimize your overall appearance.

And the best part? It’s totally free! Just enter your email address below and we’ll send it straight to your inbox.

Optimize Your Appearance

The (handsome) devil is in the details.

Enter your email address below to discover the Nine Details You Need to Nail ↓

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More Men’s Underwear & Style Advice from Irreverent Gent:
More Picks for The Best Men’s Thermal Underwear From Around the Web:
About the Author

Oluwadamilare Akinpelu

Oluwadamilare Akinpelu is a writer that mines emotion bred from words. He also doubles as a gamer and techie while supporting Arsenal. You can connect with him on Twitter @hakdown07

Banner image illustration: Irreverent Gent; Underwear shot: Meriwool