Best Thermal Underwear For Extreme Cold

Are you looking for the best thermal underwear for extreme cold? Perfect, then you’ve come to the right place!

Answer this question: Who can really stop true outdoor enthusiasts? We love the outdoors no matter what the weather is like, hot, cold, rain, or snow, nothing can keep us from where we love to be. With that being said, if we do plan on being outside during the colder months, we must make sure we are properly dressed to avoid things like catching a cold or even worse, exposing ourselves to hypothermia.

The solution to this is to make sure you are wearing a set of base layer clothing that is warm yet lightweight. You’ll want to make sure it’s breathable so you don’t start sweating. Items included in base layer clothing are long sleeve undershirts and long thin leggings. If you are indulging in outdoor activities like, snowboarding, hunting, running, skiing, or camping, then making sure you have the best thermal underwear for extreme cold is essential.

Reviews of the Best Thermal Underwear For Extreme Cold

**Below, you’ll find our more detailed reviews, but you can also click the links above to see current prices or read customer reviews on Amazon.


The Top 10 Best Thermal Underwear For Extreme Cold


1.  Duofold Men’s Mid-Weight Wicking Thermal Pant

Duofold Men's Mid Weight Wicking Thermal Pant, Black, SmallThe Duofold Men’s Mid-Weight Wicking Thermal Pant is completely versatile because of their ability to not only keep you warm and comfortable but because of its incredible moisture management and wicking components. 60% cotton and 40% polyester, with these two layers of a cotton-rich blend, combined it gives you the best attributes of both cotton and polyester. The high-quality flat locked seams will prevent you from chafing while the close-to-body fit creates a chill-blocking barrier providing you with the maximum amount of warmth. An excellent thermal selection for low-intensity activity.


  • Excellent at wicking sweat
  • Convenient front fly
  • Comfortable elastic waistband
  • Washing Machine friendly


  • Baggy near the crotch


2.  Carhartt Men’s Base Force Wicking Cotton Super-Cold Weather Legging

Carhartt Men's Base Force Wicking Cotton Super Cold Weather Bottom,Black,LargeWe all need to stay warm in the extreme cold, but some of us just can’t deal with polyester. There is a wonderful alternative to polyester long johns and it’s the Carhatt Men’s Base Force Legging. Made with 100% cotton, these thermals are excellent at doing what base layers are supposed to do, and that’s keeping you warm. They also make excellent everyday wear and with their stain breaker technology, washing out any impurities is no problem.


  • Tagless for increased comfort
  • Reinforced stitching
  • Lightweight and very durable
  • Rib-knit cuffs for extra warmth


  • Can shrink when dried
  • Elastic waistband can get tight


3.  Tesla Men’s Thermal Wintergear Compression Baselayer

TM-YUP33-KKR_Large Tesla Men's Thermal Wintergear Compression Baselayer Pants Leggings Tights YUP33If you are that super active outdoorsman, that needs thermals that are not easily torn and can keep up with you, then the Tesla Men’s Thermal Wintergear Compression Baselayer Capri Pants are an excellent option. 87% polyester and 13% spandex, this base layer is specifically designed to draw sweat and moisture away from your body all while helping your body to self-regulate even if you are in the coldest of weather conditions. Constructed with soft microfleece, equipped with elasticity to ensure a full range of motion, makes this thermal high performance and more durable compared to other base layers.


  • Keeps you warm and dry
  • Soft and breathable
  • UPF 50+
  • Flexible and allows you full range of motion


  • Sizing can be tricky (May need to order a size larger than what you think you need)
  • Can look worn after a few washes


4.  Minus33 Merino Wool Men’s Kancamagus Midweight Bottom

Minus33 Merino Wool Men's Kancamagus Midweight Bottom, Forest Green Heather, LargeIf you are looking for that perfect midweight baselayer, that is excellent for the cold and can be used for high-intensity activity, the Minus33 Merino Wool Men’s Kancamagus Midweight Bottoms could be what you’re looking for. Made from 100% merino wool, you can be sure that comfort will not be an issue. Perfect for the outdoorsman that likes to camp, fish, hike or participate in snowsports. With a UPF rating of 50+ these bottoms protect you from the sun while also being fitted enough to be worn next to the skin under an additional insulated pant. A perfect combination of, comfortability, warmth, flexibility and durability.


  • Fire resistant
  • Moisture wicking
  • Excellent at absorbing odor
  • Machine washable and dry-able


  • Can get worn down after a few months
  • Waist can stretch out over time


5.  Ekouaer Women’s Long Thermal Underwear Fleece Lined Winter Base Layering Set

Ekouaer Women's Long Thermal Underwear Fleece Lined Winter Base Layering Set (Large, Navy Blue)The Ekouaer Women’s Long Thermal Underwear is a great multi-purpose option for women who are either going to be outdoors in frigid temperatures or who need a base layer that can be worn regularly. Made with 95% cotton and 5% elastane ensures that not only will you have soft and comfortable material on your skin, but it can also stretch and allow you a full range of motion. It is also machine washable and does not shrink. Ideal for outdoor adventures and or everyday or even pajama wear.


  • Very breathable
  • Thick, and soft
  • Enhanced wicking properties
  • Double layered for increased warmth


  • Sizing runs small ( May need to order a bigger size then what you think)


6.  Men’s TCA Pro Performance Compression Base Layer Long Sleeve Thermal Top

Men's Boys TCA Pro Performance Compression Shirt Long Sleeve Base Layer Thermal Top - Mock Neck - Black Stealth LNot all base layers are made for frigid outdoor temperatures while also being able to accommodate a lot of moving around and high-level activity but there are a few that can, and the TCA Pro Performance Compression Long Sleeve Thermal Top is one of the better thermals that are specifically made for keeping you warm while being versatile enough to endure intense workouts, sports or training. The flatlock seams make this thermal super durable while the four-way stretch provides you a full range of motion, without feeling any type of restriction. The breathable fabric is made to wick moisture away while consistently regulating your body temperature, keeping you warm and dry.


  • Moisture-wicking fabric
  • Contours to your body
  • Breathable
  • Stylish


  • Can chafe under your arms


7.  Helly Hansen Men’s HH Dry Stripe Base Layer Crew

Helly Hansen Men's Lifa Stripe Crew Lightweight Breathable Moisture Wicking Thermal Baselayer, 998 Black, LargeThere are some long johns that are only meant to be base layers, and then you have others that fit as if you were wearing a regular shirt, except warmer, and more durable. The Helly Hansen Men’s HH Dry Stripe Base Layer Crew fits that description perfectly. It’s neutral fabric stays close to the skin, while keeping you nice and dry, without causing you to itch. Excellent at managing moisture during high level activities, while being lightweight and comfortable enough to be your everyday go-to base layer. You are also covered by a limited lifetime warranty. An overall excellent base layer choice.


  • Lifa stay dry technology
  • Non itch material
  • Three layer design for increased comfort
  • Low bulk cuffs, flatlock stitching


  • May not fit well if you are husky, designed for trim builds
  • Material can start to feel funny when you start sweating


8.  Pro Club Men’s Heavyweight Cotton Long Sleeve Thermal Top

Pro Club Men's Heavyweight Cotton Long Sleeve Thermal Top, X-Large, BlackIf you are going to be outdoors in the extreme cold, you need a thermal that can keep you warm, fits you comfortably and can move along with you, without it ripping or you feeling restricted. The Pro Club Men’s Heavyweight Cotton Long Sleeve Thermal Top is an excellent choice, it’s heavyweight is sure to keep you warm, while the soft cotton will keep you very comfortable. It’s casual style and its ability to maintain shape makes great for everyday wear as well. The thick waffle knit, keeps the base layer well insulated. This thermal makes excellent for outdoors, especially in low temperatures.


  • Ribbed neck and cuffs helps thermal maintain its shape
  • Can be worn as a base layer or stand alone shirt
  • Made from thick, soft cotton
  • Durable


  • Can shrink after washing


9.  Fitextreme FX Mens Maxheat Fleece Compression Performance Long Johns Thermal Underwear

FITEXTREME Mens MAXHEAT Soft Fleece Long Johns Thermal Underwear Set Navy MWhat if there was a base layer that kept you warm, kept up with your during high-intensity activity, and was comfortable. Well, there is, and it’s the FitExtreme FX Men’s MaxHeat Fleece Compression Long Johns. Being 93% polyester and 7% polyurethane, you’ll get a snugged, comfortable fit. This thermal is designed for you to be able to move freely while also helping your body to temp-regulate with its ability to wick sweat. A great choice for the outdoorsman who is on the move.


  • Very stretchy
  • Comfortable and warm
  • Stylish
  • No issues with washing


  • No front fly
  • Sizing can be tricky


10.  Liang Rou Women’s Scoop Neck Long Johns Ultra Thin Thermal Underwear Set

Liang Rou Women's Scoop Neck Long Johns Ultra Thin Thermal Underwear Set Black LIf you are searching for a versatile, multi-purpose thermal, the Liang Rou Women’s Scoop Neck Long Johns is an excellent choice as its ultra-thin material can serve as a comfortable base layer or even be used as a pajamas set. It is machine washable which means there are no issues with shrinking or stretching. Made from 95% modal and 5% spandex, this base layer gives you a comfortable feel and can stretch to move along with you. A wonderful option if you are looking quality and affordability.


  • Soft
  • Comfortable
  • Great fit
  • Can be worn as an outside shirt
  • Affordable


  • The waistband is tight


5 Questions To Ask Yourself To Make Sure You Are Choosing A Great Thermal 

How Are Base Layers Supposed To Fit?

Long johns work by helping effectively trap heat between your base layer and your skin, so they are supposed to have a snugger fit with a small gap in between, this helps your body in regulating itself by making sure you’re warm when it is cold and releasing body heat when you’re hot.

You’ll want to make sure that they are form fitting, to the point where you are relaxed but they should not hang off of you. If your thermals are too tight, it can slow down circulation, which will actually make you feel colder because your blood is not properly running through your body.

What Temperature Are They Recommended For?

Base layers are really meant to be accommodating in a variety of different weather situations but usually when it is colder. A great quality thermal will serve as a wicking base layer, if you are moving around a lot and serve as a thermal layer if you are not as active.

How Thin Are Thermals?

When choosing the right thermal underwear for you, it’s best to find that perfect blend between your thermals being thin, while still being lightweight and warm. In general, the thicker a base layer is, the warmer you’ll be.

Do I Need A Moisture Wicking Base Layer?

If you plan on being active while wearing your base layer, then you’ll want to make sure that it has wicking properties. This will ensure that your thermals draw the moisture from your body, away from you, into the clothing. In conjunction with your thermals wicking effectively, that’s not the only thing that would cause you to be uncomfortable. You also want to pay close attention to how quickly your base layer dries, the quicker it can dry, the less cold you’ll feel once you stop moving from all the moisture that they’ve absorbed.

Should I Choose Wool Or Synthetic?

Wool: Wool is naturally form fitting and looks better on a lot of people. It’s natural wicking properties and breathability is far superior to synthetic material. It naturally is better insulated and feels very warm, even though it does not dry as quickly as synthetic does. If you plan on camping or being around fires or anything that can spark a fire, wool is a lot less flammable but since wool does not dry as quick, it’ll be a better option if you are not going to be as active and sweating or if you are active in colder weather, where you will tend to sweat less.

Synthetic: Synthetic dries a lot faster than wool does, while being far more inexpensive as well. Perfect if you plan on doing any outdoor sports or activities that will cause you to sweat a lot. People who love to backpack or needs to carry heavy equipment may find that synthetic material accommodates them more than a heavier wool does.


What Attributes To Look For In Good Quality Thermal Underwear


Having a base layer that is breathable means that it has the ability to help your body temp-regulate itself. You’ll find that wool long johns are usually more breathable than other fabrics because it is more lightweight and form-fitting. The closer your base layer is to your skin, without being too tight, usually, the better it keeps you nice and warm when the temperature dips.


This could be single-handedly the most important attribute you’ll want to look for when choosing thermal underwear because no matter how well the wicking is, how inexpensive the price is or how nice it looks, none of that matters if you are uncomfortable. Comfortable is a relative term, it means something different to everyone but some good questions to ask yourself when making your selection is: Can I move the full range in it? Does it make me itch? Is it too loose or too tight? Is the fabric soft or stiff? Does it keep me warm? Answering those question will give you a better idea of what you are looking for and what feels most comfortable to you.


Having thermals that are durable will determine if you’ll be using them for one year or several. To make sure your base layer is durable you’ll want to take a closer look at the type of fabric it is made from, while also researching the reviews to see if others are having issues with rips and tears.


Wool and synthetic both have coatings that deem to be anti-odour, but some base layers will hold a smell better than others because of their antibacterial properties. This may not be at the top of your list of concerns, but if you will be active and sweating during the time you’ll be wearing your long johns, how well they can hold odour is worth looking into.


It is definitely possible for base layers to be used in extremely cold weather, you just want to make sure that they have a comfortable snug fit so they can properly help your body temp-regulate itself and do a better job of keeping you warm.

Drying Time

Another property you’ll want to pay attention to if you will be active is how quickly your long johns will dry after pulling moisture from your body. If the drying time is long, it could mean that after your thermals pull in your moisture you’ll feel that dampness on you, which in the extreme cold is really uncomfortable.



In this article, we’ve compared some of the highest quality thermals on the market and broken them down into what makes them great like their ability to wick sweat, how durable they are, their comfortability, how well they hold odor and how warm they’ll keep you.

Based on all of the above criteria, the best thermal pants are the Duofold Men’s Mid- Weight Wicking Thermal Pant. They perform extraordinarily in each category while still being affordable.

The best base layer top is the Men’s TCA Pro Performance Compression Base Layer Long Sleeve Thermal Top. Besides it being comfortable, being able to keep up with high-level activity and wicking away sweat flawlessly, it is also stylish and can possibly serve as an outer layer as well as a base layer.