Feeling the winter chill? Winters can be brutally cold at times but staying bundled up close to fire isn’t always an option. Whether you’re going out for work or any outdoor activity, thermal underwear is a must when it’s all snowy outside.
It is a thin piece of clothing worn under clothes to keep the body warm. Unlike regular underwear, it is made from specialty fabric that wicks away moisture or sweat from skin to prevent dampness and cold setting in.
It is so closely knitted that it retains body heat without requiring you to layer multiple clothes. It is ultra-warm, light-weight and breathable for all-day comfort. In fact, most of these are anti-bacterial and odor-resistant, so you can wear them for 3-4 days if required.
Top 10 Best Thermal Underwear Comparison Table
| Picture | Name | Features | Rating (1-5) | Price |
|---|---|---|---|---|
 | Hanes Men's Red Label X-Temp Thermal Pant | Double layer fabric with waffle knit pattern X-Temp technology Shrinkage protection 3 color options Low price | 3 | $ |
 | Carhartt Men's Base Force Wicking Cotton Super Cold Weather Bottom | 100% soft cotton FastDry technology Reinforced stitching and rugged cuffs Shrinkage protection Stain Breaker technology 3 color options | 3 | $$ |
 | Moet Fashion Men's Ultra Soft Thermal Underwear | Double layer, fleece-lined fabric Four way stretch 5 color options | 3.5 | $ |
 | Fruit of the Loom Men's Classics Midweight Thermal Bottom | Double layer fabric with waffle knit pattern Extremely Light-weight Shrinkage protection 3 color options Low price | 4 | $ |
 | Duofold Men's Mid Weight Wicking Thermal Pant | Double layer fabric Flat-locked seams and rugged rib knit cuffs 5 color options Low price | 5 | $ |
 | Women's Thermal Underwear Set Top & Bottom | Double layer fabric with fleece lining 17 color options Heavy online discount | 3 | $ |
 | Rocky Womens Thermal 2 Pc Long John Underwear Set | Double layer fabric Fleece lined bottoms Crew neck and long cuffs Shrinkage protection 11 color options | 3.5 | $ |
 | FITEXTREME FX Womens MAXHEAT Fleece Long Johns Thermal Underwear Set | Double layer, fleece lined fabric Four-way stretch Option to buy top & bottom separately 4 color options | 4 | $$ |
 | Tesla Blank Women's Top & Bottom Set w Microfiber | Double layer, fleece lined fabric Four-way stretch Extremely light-weight Heatfit design Shrinkage protection 8 color options | 4.5 | $ |
 | ultradry Outland Women's Thermal Set | Double layer, fleece lined fabric Four-way stretch Extremely light-weight Shrinkage protection Combo pack with an extra shirt | 5 | $$ |
It is indeed a useful product but, we have so many brands specializing in producing thermal clothing that choosing the best thermal underwear is a daunting task.
To make things easy, we have come up with this comprehensive guide that includes everything you need to know when buying thermal underwear.
Here, you’ll get to know not just their types, benefits and downsides but also the best options to purchase, so stay tuned.
What types of Thermal Underwear Are There?
There are five main types of thermal underwear depending on the fabric used. These are typically made of cotton, synthetic, wool, silk or bamboo.
Cotton thermal underwear is a low price option but it tends to retain moisture as you sweat. It can be used to stay warm inside home or when you are not highly active but for outdoor pursuits, it is not very effective.
The synthetic ones are largely made from polyester and polyester blends. Polypropylene is one of the most used synthetic fabrics.
These are light-weight, quick-drying, machine washable, durable and relatively cheap. However, they are not antibacterial or as warm and odor-resistant as merino wool.
Woolen or fleece thermal underwear is the warmest type of all. To be more precise, it is merino wool that’s most commonly used. Unlike traditional wool, it doesn’t itch or collect odors. It is soft, warm and regulates body temperature well.
It maintains body heat even when wet and since its air pockets draw away excess heat from the body, it also prevents overheating after exercise.
It is anti-bacterial and can be worn for extended periods of time. For the eco-conscious users out there, it is also biodegradable (in under a year) unlike synthetics. It is more expensive though.
Silk thermal underwear is very thin and soft but its wicking ability is low if compared to synthetic fabrics. They are usually chemically treated to enhance their wicking properties.
Bamboo is a more recent entry into eco-friendly clothing. Since it is a natural fiber made from bamboo grass pulp, it is a nice alternative for those who have sensitive or allergy prone skin.
It is antibacterial, itch-free and odor resistant. The cross-section of this material has various micro-gaps that enable much better moisture absorption and breathability than other fibers.
The wicking quality is similar to merino but 3-4 times better than cotton. Its micro structure also keeps it warm in cold weather and 2-3 degrees cooler in warm weather, allowing better body temperature regulation.
Bamboo underwear does not stick to skin but gives a closer fit than merino wool. Also, it is more durable and soft against skin.
Bamboo cuts out 97.5% of harmful UV rays, so unlike any other underwear, it provides UV protection and is great for overall health. However, there are very limited bamboo underwear options and these are quite expensive too.
Of all the above, synthetic and woolen thermals are most commonly used.
Benefits of Best Thermal Underwear
One of the easiest ways to stay healthy is by wearing high quality thermal underwear. It helps maintain the normal body temperature without any significant drop or raise, thus boosting heart function, blood circulation and general health.
When you sweat, heat is drawn away from body through evaporative cooling and the body temperature drops, which is definitely not what you want on a cold day.
On the other hand, if the sweat is not removed from your body, it increases the risk of hypothermia and may even weaken the immune system.
Thermal underwear, with its wicking qualities, sucks all sweat off your skin while keeping you warm. Ideally, its fabric should be able to respond to changing body conditions and provide warming or cooling effects depending on the body temperature.
The underwear should be tight-fitting for heat retention and support but also breathable for comfort. A good rule of thumb is that the colder the temperature is, the heavier should be the fabric.
But too thick or bulky is also not good. The best thermal underwear helps cut extensive layering and keeps you warm without anyone even knowing you have it on. High quality equals to high efficiency!
Also, the best pairs are bacteria and odor resistant so that they can be worn for days if required.
Downsides of Thermal Underwear
Caring for thermal underwear is not always easy. They require only a mild detergent and any type of bleach, fabric softeners or specialty cleaners do not work well with them.
Bleach or harsh detergent weakens their tightly woven fibers and fabric softeners interfere with their wicking ability. Also, they are known to shrink if washed with hot water. They are usually costly and require special maintenance.
10. Hanes Men’s Red Label X-Temp Thermal Pant
Hanes is one the most well-known clothing manufacturers. Like their other products, the Red Label X-Temp underwear is very comfortable and durable.
Made of a cotton poly blend of 60/40 respectively, it is tight fitting and yet breathable. Since the material is designed to be the first layer, it provides enough support, compression and wicks away all sweat effectively.
Its waffle knit pattern not only locks in the heat but also helps the material maintain its structure.
Thanks to its X-Temp technology, it adapts to the body temperature well and provides warming or cooling effect as required. Another good thing is that it is machine washable and chemically treated for shrinkage control.
It is available in black, grey and natural colors and all sizes from small to XX large. It is snug fitting, so buy a larger size if you prefer a looser fit. Overall, it’s a nice product and pretty affordable too.
Pros:
- Double layer fabric with waffle knit pattern
- X-Temp technology
- Shrinkage protection
- 3 color options
- Low price
Cons:
- Some users complained that the inseam is longer than required.
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9. Carhartt Men’s Base Force Wicking Cotton Super Cold Weather Legging
This thermal underwear is made from 100% cotton (9.5 oz. and ring spun) and is naturally anti-bacterial. Unlike most other thermal wears, it has no trace of synthetics.
If you have sensitive or allergy prone skin, this is probably the best thermal underwear for you.
It is lightweight, soft and imbued with FastDry technology to wick away all sweat in no time. It also has reinforced stitching and rib-knit cuffs that seal in the body heat no matter what you’re doing.
The waist line is flexible, so it can fit different waist sizes comfortably. It is semi form-fitting, so it does cling to the body but allows easy movement as well.
This is especially useful for those who feel that skin tight is just too tight for them. It is machine-washable and thanks to its Stain Breaker technology, all stains are easily released in one wash.
Also, it shrinks negligibly after washing, unlike most other thermal wears. Carhartt Men’s Base Force underwear is available in 3 different colors (black, grey and natural), so you can pick the one you like.
It is a nice, well made product and is meant to last for years.
Pros:
- 100% soft cotton
- FastDry technology
- Reinforced stitching and rugged cuffs
- Shrinkage protection
- Stain Breaker technology
- 3 color options
Cons:
- Some users complained that the bottom cuff is too long and tight, making it difficult to put on and take off the leggings.
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8. Moet Fashion Men’s Ultra Soft Thermal Underwear Long Johns Set With Fleece Lined
This one is a two-piece set with a long sleeve top and bottom. Made from 92% polyester and 8% spandex, it is stretchable and breathable.
The material is ultra-soft and lightly fleece lined for added warmth and thermal insulation. This Moet Fashion underwear set can be used as a base layer when going out or as a pajama set indoors.
It is thin and light-weight but the warmth-to-weight ratio is high, so it is definitely an effective product.
It is available in a lot of colors (black, navy, white, grey and light grey) and sizes to appeal all segments of users.
Also, it is machine washable and quick drying. It is reasonably priced and surely worth considering when buying a new set.
Pros:
- Double layer, fleece-lined fabric
- Four way stretch
- 5 color options
Cons:
- Sizes are smaller than the conventional brands, so you need to purchase at least one size up to enjoy perfect fit.
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7. Fruit of the Loom Men’s Classics Midweight Thermal Bottom
Fruit of the Loom is one of the oldest brands and is known for quality and style. Staying true to their roots, these bottoms are sturdy, durable and nice-fitting.
Made from a blend of 60% cotton and 40% polyester, it is stretchable, comfortable and wicks all moisture efficiently.
There is also a touch of spandex in the ribbed cuffs so that they stay snug on your ankles. The product is warm and makes a great layering piece.
Its waffle knit pattern, smooth flatlock seams and sturdy seam construction- all help in heat retention.
The waistband is elastic and tag free for itch-free comfort. Because it is available in small to 5X large sizes, finding the right fit is easy for everyone.
It comes in black, grey and natural colors and can be paired with Fruit of the Loom’s Men’s Classic Midweight Thermal Crew Top which can be purchased separately.
It is machine washable and has zero to negligible shrinkage. Overall, it is a nice, low price product and offers great value for money.
Pros:
- Double layer fabric with waffle knit pattern
- Extremely Light-weight
- Shrinkage protection
- 3 color options
- Low price
Cons:
- Some users complained that it is too thin to be sufficiently durable.
6. Duofold Men’s Mid-Weight Wicking Thermal Pant
This Duofold Thermal Pant is made from a blend of 60% cotton and 40% polyester. The material is warm, stretchable and wicks away all moisture from skin.
This is a thin, mid-weight pant and is ideal for layering under jeans or other outfits for workouts.
It has a nice snug fitting, a soft texture-rich knit, a pull on closure and flat-locked seams for better thermal insulation and no chaffing.
The waistband is tag-free and the rib-knit cuffs are also comfortable. It comes in all sizes from small to XX large and has an adjustable inner drawstring and convenient front fly for perfect fit.
There are plenty of color choices (black, red, navy blue, white and forest grove) as well. The thermal wear is of ankle length and has a simple design for convenient wearing and removal.
It is machine washable but may shrink a bit after repeated use & wash. It is a reasonably priced product and a good option to consider.
Pros:
- Double layer fabric
- Flat-locked seams and rugged rib knit cuffs
- 5 color options
- Low price
Cons:
- Some users complained that it shrunk significantly just after one wash.
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5. Women’s Thermal Underwear Set Top & Bottom Fleece Lined
Unlike all above, this is a two-piece set for women. The material is a blend of 92% ultra soft polyester and 8% spandex. It has a silky feel on the outside and a fleece lining inside.
The top and bottom- both fit snug enough that there are no wrinkles showing when worn under clothes.
The length of the top and sleeves are a bit shorter than usual, so this allows you to hide it under any of your jackets or sweaters.
The set is warm, thin and extremely comfortable. It can be worn as base layer or also as sleepwear. It is machine washable and easy to care for. It comes in varied colors, not just the common ones.
You can get it in grey, light grey, black, candy pink, white, deep blue, soft beige, brown, red, dark purple, army green, burgundy, light orange, bright red, olive, pink and royal blue shades.
It has a nice slim fit, looks great and is available online at a discounted price.
Pros:
- Double layer fabric with fleece lining
- 17 color options
- Heavy online discount
Cons:
- Some users complained that sizes are smaller than conventional brands. It is advisable to get one size larger from what you’d normally order.
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4. Rocky Womens Thermal 2 Pc Long John Underwear Set Top and Bottom Smooth Knit
This two-piece set from Rocky Women features a long sleeved top and a fleece lined bottom. The material is a blend of 55% cotton and 45% polyester, making it very thin and light-weight but warm.
Note that the material is thin but not see through at all. The set is stretchable, breathable and can be used as an athletic wear for outdoor activities like hiking and skiing.
It is semi-form fitting and so comfortable that many users prefer using it as sleepwear.
Its smooth thermal knit, crew neck and long cuffs help retain body heat. The bottoms have a thermal resistant elastic waistband and are of ankle length so that they do not show outside when worn under jeans.
Also, the set is shrinkage controlled for lasting size and shape. Like most sets for women, it comes in a wide range of colors. It is available in hot pink, baby pink, teal, black, purple, white, red, navy blue, royal blue, rust and yellow colors.
It is a beautiful set and quite popular too.
Pros:
- Double layer fabric
- Fleece lined bottoms
- Crew neck and long cuffs
- Shrinkage protection
- 11 color options
Cons:
- The neck is crew cut to cover the upper part completely but some users felt that it’s uncomfortably tight.
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3. FITEXTREME FX Womens MAXHEAT Fleece Compression Performance Long Johns Thermal Underwear
FitExtreme is one of most popular thermal underwear brands in South Korea. Its MAXHEAT underwear is a high quality product made from 93% polyester and 7% polyurethane.
It is a four-way stretch material and feels very soft on skin. It has excellent wicking ability and is resistant to odor, so there is no sweat or smell.
The set offers nice compression, support and seamless semi-form fit, allowing complete freedom of movement while making the body look slimmer.
Also, it is lined with soft fleece, acting like a thin blanket even without being noticed. Unlike most other sets, the top and the bottom can be purchased separately.
This helps to mix and match the colors. The set is available in black, navy blue, light grey and dark grey colors. It is machine washable and easy to care for. This is a well-made, comfortable product and is designed to last for years.
Pros:
- Double layer, fleece lined fabric
- Four-way stretch
- Option to buy top & bottom separately
- 4 color options
Cons:
- There have been size inaccuracies and it is advisable to get one size larger from what you would normally order.
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2. Tesla Blank Women’s Top & Bottom Set w Microfiber WHS200
The Tesla Blank underwear set is made from a unique blend of 92% ultra soft microfiber and 8% spandex that gives it superior insulation and moisture wicking ability.
The material has super elastic fibers for 360 degrees free mobility and slim fit. Also, it is micro fleece lined for extra warmth.
The set has a nice, sporty design and can be used as an athletic wear for outdoor activities. It is very thin and weighs less than 3 ounces.
If you prefer something very light-weight, this is probably the best thermal underwear you can get. It has an innovative heatfit design for thermal insulation and an extra smooth and soft interior, so it also makes a great sleepwear option.
It can be washed in machine and since it is chemically treated for shrinkage control, it retains the original shape and size.
It comes in all sizes from X small to X large and a plenty of color options including pink, black, white, red, grey, navy blue and purple. It has a nice sheen and looks more expensive than it is.
Pros:
- Double layer, fleece lined fabric
- Four-way stretch
- Extremely light-weight
- Heatfit design
- Shrinkage protection
- 8 color options
Cons:
- It is a very tight-fitting set, especially the bottoms. Order one size up for a more comfortable fit.
1. Ultradry Outland Women’s Thermal Set, Base Layer, Lightweight Ultra Soft Interior Fleece Shirt and Tights
Like the name suggests, this is a quick drying product with excellent wicking ability. It is made from 92% ultra soft polyester and 8% spandex, so it is ultra soft, thin and stretchable.
The Ultradry Outland Women’s Thermal Set is a combo pack with 2 shirts and a pair of tights.
The set has a tailored fitted women’s design that helps retain body heat. Also, it has a micro fleece lining for extra warmth. It can be used as base layer or worn alone as sleepwear or athletic wear.
It does not restrict movement and feels like second skin. It is machine washable and since it is treated for shrinkage control, it stays true to the original size. Also, the material does not fade and always looks like new.
The product comes in sizes from XS to 5XL, so women of all sizes can find their perfect fit.
It is available in black and also a camouflage print that’s rare in underwear sets. If you like camouflage printed clothing, this set is a must-have. It is stylish, warm and makes one feel beautiful.
Pros:
- Double layer, fleece lined fabric
- Four-way stretch
- Extremely light-weight
- Shrinkage protection
- Combo pack with an extra shirt
Cons:
- Unlike most other underwear sets for women, color options are limited to only two.
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Editors Choice of Best Thermal Underwear
Out of all the listed options, we found Ultradry Outland Women’s Thermal Set to be the best thermal underwear.
Unlike any other thermal wear, its material has highest warmth to weight ratio and keeps you warm even in very cold temperatures.
It is a very quick-drying, warm set with a bonus of extra shirt in low price. The design is also stylish and users are very happy with the way it fits.
It does not even shrink or fade after repeated use and wash. All this makes it a great deal and we have no major reason to complain. We love it and also recommend it to our readers.
Which one do you think is the best thermal underwear? Do share your views by leaving your comments in the box below. If you have used any of these products, we would love to know your experiences.
Of course these thermal sets come in handy for outdoor activities especially for winter sports. But of course some of these sports such as hockey can be found indoors with cold environments too.
Regardless of indoor or outdoor hockey, they’re both usually cold and thermal underwear can be the perfect fit for you!
