Best Thermal Underwear for Men (Winter 2019-2020)

Best Thermal Underwear for Men

Thank you for visiting our Best Thermal Underwear for Men list.  We also have a list for the best women’s thermal underwear and the top thermal socks

Winter is here and we all need warm, yet soft and comfortable clothing to keep our bodies protected from the cold temperatures. By sticking with the best thermal underwear for men listed below, you’ll be able to achieve this.  In fact, recently the best thermal wear brands have developed products that are much more versatile than in years past.  It used to be the case where you would grab your one trusty pair of long johns for a cold football game and bury them under your normal street clothes where they couldn’t be seen.  That’s just not the case anymore.

There’s special thermal wear for all kinds of activities these days.  Need something think and lightweight for a run on a brisk morning or to wear under your suit to the office?  No problem, it’s covered.  Need something entirely different and warmer for heading out in the woods to hunt or to go winter camping?  We’ve got you covered there also.  No matter what the occasion or activity, someone makes that piece of thermal wear for men.  It feels good and looks good too.

The best mens long underwear are made of high quality materials and aren’t cheap.  They’ll keep you warm and dry when you need it most.  Rather than buying 5 sets of cheap thermals, you’re better off buying one really good set of mens long johns, preferably made of merino wool.  More on materials below in our buyer’s guide, but first here’s our top 5 list of the best thermal underwear for men. 

The WoolX Men’s Base Layer is a thermal made from 100% Australian merino wool and comes in different weights, from lightweight to heavyweight. WoolX merino wool is one of the softest, most high performance materials, and it’ll keep you warm without adding bulk. It’s great to wear during work, exercising, or even out hunting. The best part is that it wicks moisture from your skin and resists odors.  It’s also machine washable and dryer safe with no shrinkage.  WoolX offers a 100% satisfaction guarantee stating that you can return it for a full refund or exchange if you’re not happy with it.  

We think WoolX makes the best mens base layer.

WoolX Merino Wool Men's Thermal Underwear


> Keep warm –  merino wool is the best material for thermal wear

Versatile – Can be worn as a base layer or can be worn alone.

> Guarantee – 100% satisfaction or your money back

Wide range – WoolX offers the best mens thermals in 3 different weights (light, mid, heavy)


> WoolX only uses high-quality merino wool so they aren’t cheap!

> Many of their products are only offered in black

LAPASA thermal wear for men comes in different materials.  They offer 100% merino wool, fleece-lined thermals, and waffle knit like your old-school long johns from the 90s.  This is nice because they you can choose your quality, and thus the price-point, based on your specific needs.  With merino wool being the warmest, highest quality, then fleece-lined, and waffle knit at the end of lower cost options.  Another unique feature of LAPASA is that they sell their thermals in long john sets that include a top and bottom together.     

With the selection LAPASA offers, they are our go to brand for the best long johns on Amazon!

LAPASA - Best long johns


> Keep Warm – merino wool is the best material for thermal wear

> Sets – Includes both top and bottom long johns

> Materials – 3 different options & price-points

> Colors – Several color options 


>  Confusing offering – so many options it can be confusing

Tesla Wintergear is a compression fit men’s thermal underwear that is 87% polyester and 13 % spandex. This material has a very quick dry time.  The flexibility that it provides makes it an excellent choices for many indoor and outdoor activities and sports.  Its warmth design makes it an excellent choice for several outdoor and indoor activities.  It also safeguards your skin from harmful UV rays (UPF 50+).  Please note that it’s advisable that you order one size larger than you would normally wear. 

The materials used in Tesla’s thermals make it the best affordable men’s base layer available on Amazon!

Tesla Wintergear


> Flexibility – Easy to move around in, great for sports

> Great price – Very affordable 

> Versatile – Can purchase in sets or separate 

>  Colors – Several color options


> Extreme Cold – Material thin & not adequate for extreme temps.

As the legacy of a 100+ year old USA based wool company, Minus33 brings you the best thermals for extreme cold weather. Minus33 merino men’s Yukon thermals are made of 100% merino wool which make them very warm and soft.  They are low maintenance as they are machine washable and dryer-safe.  As with all merino wool products, the Minus33 men’s thermals a great at wicking moisture and sweat away from your skin to keep you dry and odor-free.  Minus33 stands behind their products and offers a 30-day refund or exchange if you’re not happy with your purchase. Lastly, Minus33 thermals look great and can be used for more than just a base layer.  Even though they aren’t cheap, they are a good value!

Minus33 products are the best thermals for cold weather, and therefore are also the best thermal underwear for hunting.

Minus33 mens long underwear


>  Versatile – Can wear under clothes or stand-alone

>  Fashionable – They have more fashionable options

> Keep warm – Merino wool is the best material for thermal wear


>  Price – Minus33 uses high-quality materials and is not cheap

FitExtreme men’s MAXHEAT compression performance long Johns thermal underwear is made of 93% Polyester and 7% Polyurethane.  This is a premium silky soft fleece lining for excellent comfort and cold weather warmth.  There is tons of freedom in movement and they are actually very slimming in appearance.  Some of the material qualities include thermal retention, sweat wicking, quick-dry, and light weight.  They aren’t the warmest mens long underwear for extreme cold weather conditions, but they are a comfortable and very affordable option. 

These are the best thermals for men if compression, flexibility, and price-point are the most important factors to you.

FitExtereme MAXHEAT Compression Thermal Underwear


> Thin and light weght

>  Affordable option for everyone

>  Available as a set or separates

>  Great for layering


>  Not as warm as merino wool, but is a great extra layer

best thermal underwear for men:  buyer's guide

Best Mens Long Underwear: Buyer’s Guide

With all the options of materials and weights, it’s easy to understand why looking for the best mens long underwear can be a daunting task.  We’ve populated this buyer’s guide to help with your approach.  It should help you determine what factors to consider when you’re ready to buy.  After all, each of the items above is great in its own right.  Each has features and properties that make it unique and popular for specific uses. 

Best Thermal Underwear Materials

There are several materials to make great thermal clothing out of.  The best materials keep you warm of course, but also dry, and aren’t too think that they are hard to move around in. 

Merino Wool

Merino wool is by far the most popular material used in the best thermal wear brands such as WoolX and Minus33.  Wool has balanced thermal insulation characteristics, that is, it is warm in winter but cool in summer. It is very resistant to wrinkles.  It has a natural crimp that allows it to return to its natural shape even after being stretched by up to 30%.  In additional to keeping its shape, wool is also hypoallergenic, naturally renewable, eco-friendly, and sustainable for our environment.  It’s also anti-static and naturally flame-resistant.  And, on top of all that, it’s moisture-wicking, keeping your skin dry and reducing odors.  There is no doubt that merino wool makes the warmest mens thermal underwear.   

merino wool


Polyester is a readily available and relatively inexpensive fiber material.  It’s extremely versatile, flexible, and durable.  Polyester thermals are especially easy to maintain as they are easy to clean through standard machine wash and keep their shape.   The compressive feeling of the polyester makes for comfortable, yet very durable thermal underwear.  Because of inexpensive nature of polyester, thermals made of this material tend to be very affordable.  



Cotton is actually not a very good material for thermal underwear.  It’s an especially poor fit if you’re doing any sort of activity.  It can become saturated with sweat and take a long time to dry out because it retains the moisture.  It’s a much better warm weather material.  I do not recommend cotton thermal underwear.


So which material should you choose? It depends on what you’re looking for. If you want something to keep you ultra-warm in the coldest of environments, merino wool is the best men’s long underwear fabric. This is a great choice for hunting, camping, cutting firewood, or at a football game. This is also the best option if you only plan on getting one set of men’s long underwear, as it’s the most versatile.   

If you’re looking for an added layer in cooler temperatures and will be doing physical activity, polyester might be a better fit. It’s more flexible and gives a compressive fit that is easy to move around in. Polyester is also thinner and fits well under clothing for in an office setting.  It’s also lower cost if you won’t be in the more extreme cold temperatures. With the prices of polyester thermals coming down like you see in the Tesla and FitExtreme options above, I see no reason to purchase cotton thermal wear.  Cotton is used because it is so cheap, but polyester is also inexpensive and does a much better job!


Common Uses for Thermal Underwear

There are quite literally an unlimited number of uses and reasons for buying thermal underwear.  Really anything you do where you want to be warmer is a great start.  Some of the more common activities where thermal wear is used are listed below:

> Hunting, camping, hiking and other outdoorsy activities

> Watching sporting events – football, soccer, hockey and more

> Running, walking, and biking

> As pajamas or just lounging around the house during the winter months

> As a base layer under your clothes for work, school, shopping, etc.


Does Thermal Wear Work

Yes!  It works by insulating the air around your skin.  It also wicks the sweat and other moisture away from the skin to keep that air dry so it doesn’t feel cold.  By having this warm, dry insulating layer, your body heat keeps you warm.  If that air pocket is allow to escape or becomes wet it would become cold and no longer be effective.


How to Wear Thermal Wear

It’s important to get thermal wear that fits well.  If it’s too loose, the insulated air that is supposed to be trapped next to your skin will exchange with other, cool air and not retain the heat.  Thermal clothing should have semi-tight fit so that air stays trapped, but not so tight that it’s uncomfortable.  This would mean there not enough air for that insulating layer to form.

Best Thermal Underwear for Men FAQs

Best Thermal Underwear for Men FAQS

Here are some frequently asked questions we found during our research for this article.  I wanted to answer them here in case you had the same question.  Please let us know if you have additional questions.

Q:  What material makes the best men’s base layer?

A:  Merino wool makes the best men’s base layer because it insulates well and wicks moisture to keep your skin dry and odor-free.

Q:  How do I know where to buy thermal underwear?

A:  The best place I know where to buy thermal underwear is Amazon.  They have the largest selection, great prices, and many items have free shipping (2 day shipping if you have Amazon Prime).

Q:  Is silk warmer than wool?

A:  No, wool is much warmer than silk because it traps the heat in.  Merino wool is the material that is makes the warmest mens thermal underwear.

Q:  What is the best thermal wear brand?

A:  Considering all types of thermals for both genders, it’s a toss-up between Minus33 and WoolX.  Both are great and have wonderful products.

Q:  Should you wear underwear under thermal underwear or long johns?

A:  Technically speaking the base layer material is likely far better for insulation and moisture-wicking than your run of the mill cotton boxers or whitie tighties.  However, if there’s a chance you’ll want to shed the base later later on, it might be a good idea to have them with you.

Q:  Should a base layer of your thermal clothing be tight?

A:  It should be snug so that it traps the air that your body heat keeps warm, but not too tight that the insulated air pocket doesn’t exist.

Q:  What material makes the best ski thermals?

A:  I suggest starting with merino wool.  It’s warm, moisture-wicking, and flexible.  See #1 on the list above!

Q:  Why don’t you recommend mens cotton long underwear?

A:  Cotton is an affordable material, but it retains moisture against your skin and breathes so it lets the heat out.  Polyester is similar in pricing to cotton and has more of the properties we need for thermal underwear in it.

Q:  Can you wear two base layers?

A:  Sure. In some cases, two thin base layers might be less restrictive and allow more flexibility in whatever activity you’re doing.

Q:  Can you tell me how to wear thermal wear?  I don’t understand which layer goes where.

A:  You want to start with the best thermal base layer that will keep your skin warm and dry.  Then the mid layer can be heavier and insulated.  Lastly, the outer layer is like a shell.  It should be waterproof (or water resistant) and also block the wind.  See below for more details.

Q:  How many layers should I wear in the winter?

A:  Three layers should suffice if done correctly.  See the layering infographic below as a guide

Thanks for reading our post about the Best Thermal Underwear for Men.  Click below to see the other two parts of our best thermal clothing articles

Best Thermal Underwear for Women

Best Thermal Socks