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Best Thermal Wear for Extreme Cold

last updated Jan 14, 2019
Layering is like second nature to anyone who works in or enjoys activities in extremely cold climates. It is really a necessity. The design and technology used have to work, you have to know that when you go out with this clothing on that you will be protected and be able to function. When we reviewed products that fit into this category of those that offer serious production and strength we narrowed it down to the 10 best. This list was particularly hard to put together because each of these products is just so good on its own. It was extremely hard deciphering the order but there were little features that made us get it together and put an exacting list with the most tedious critical review of each. For all items, we evaluated them using the basic criteria of materials, weight, and fit.

In a Hurry? The test winner after 17 hrs of research

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Minus33 Merino Wool Kancamagus
97.3/100 our score
Materials
99
Weight
99
Fit
94
Minus33 Merino Wool Kancamagus
Why is it better?

100% Merino Wool

Lower body pant base layer

Soft and comfortable with easy care, this product is machine washable and dryable

Sizes XL-6XL and Tall sizes M-Tall to 4X-Tall

Reputable brand with over 100 years of experience

UPF 50+

In a Hurry? Editors choice:
Minus33 Merino Wool Kancamagus
Test Winner: Minus33 Merino Wool Kancamagus
Researched Sources
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17
Hours Researching
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1
The rating is based on the average rating (1-100) from all the criteria in which we rated this product.
97.3
Materials
99%
Weight
99%
Fit
94%
Price Comparison Last Updated (22.01.19)
$65.99
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$75.99
2
The rating is based on the average rating (1-100) from all the criteria in which we rated this product.
97.3
Materials
98%
Weight
99%
Fit
95%
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$26.00
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3
The rating is based on the average rating (1-100) from all the criteria in which we rated this product.
96.7
Materials
97%
Weight
98%
Fit
95%
Price Comparison Last Updated (22.01.19)
4
The rating is based on the average rating (1-100) from all the criteria in which we rated this product.
95.7
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97%
Weight
95%
Fit
95%
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$29.99
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$49.95
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5
The rating is based on the average rating (1-100) from all the criteria in which we rated this product.
95
Materials
95%
Weight
96%
Fit
94%
Price Comparison Last Updated (22.01.19)
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The rating is based on the average rating (1-100) from all the criteria in which we rated this product.
94
Materials
94%
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95%
Fit
93%
Price Comparison Last Updated (22.01.19)
7
The rating is based on the average rating (1-100) from all the criteria in which we rated this product.
92.7
Materials
92%
Weight
93%
Fit
93%
Price Comparison Last Updated (22.01.19)
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The rating is based on the average rating (1-100) from all the criteria in which we rated this product.
90
Materials
92%
Weight
88%
Fit
90%
Price Comparison Last Updated (22.01.19)
9
The rating is based on the average rating (1-100) from all the criteria in which we rated this product.
86.7
Materials
87%
Weight
85%
Fit
88%
Price Comparison Last Updated (22.01.19)
$22.49
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$35.73
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10
The rating is based on the average rating (1-100) from all the criteria in which we rated this product.
87.3
Materials
87%
Weight
89%
Fit
86%
Price Comparison Last Updated (22.01.19)
In Depth Review Top 10
  • Minus33 Merino Wool Kancamagus
  • Darn Tough Vermont Merino Wool
  • J.B. Extreme - 30t
  • Carhartt Base Force
  • ColdPruf
  • First Lite Allegheny
  • Icebreaker Merino Everyday
  • Tasc Performance
  • Columbia Midweight
  • Duofold Heavyweight
Table of contents
  • Criteria Used for Evaluation
  • Other Factors to Consider
  • Frequently Asked Questions
  • Sources

Top 10 Best Thermal Wear for Extreme Cold

1. Minus33 Merino Wool Kancamagus

The rating is based on the average rating (1-100) from all the criteria in which we rated this product.
97.3
Minus33 Merino Wool Kancamagus
Materials
99
Weight
99
Fit
94
best offer for today
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$75.99
$65.99
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Pros:

100% Merino Wool

Lower body pant base layer

Soft and comfortable with easy care, this product is machine washable and dryable

Sizes XL-6XL and Tall sizes M-Tall to 4X-Tall

Reputable brand with over 100 years of experience

UPF 50+

Cons:

These can stretch out over time with consistent use

Thin base layer

Made from 100% Merino Wool, this is a seriously warm baselayer legging for the lower body with a wide range of sizes to help fit most sizes, XS to all the way up to 6 XL. The company has a serious street rep, with over 100 years as a US-based woolen company that provides the best merino wool products to market at the most reasonable prices.

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Natural Functionality
This product is naturally perfect. Merino wool is breathability and can help with moisture management, it is a four-season fiber as it can keep you incredibly warm while also maintain your coolness, it is odor resistant as well as strong, and this is all in its natural makeup. It is amazingly soft as well, beating out the cliche of itchiness when one thinks of the feel of wool. This baselayer offers such tremendous functionality as mentioned above due to this special, natural material, it also offers a rating of UPF 50+ so that it can protect your skin from intense sun rays, especially those that are magnified by reflecting off of crystalline white snow.

Practical
Literally, there aren’t any sizes that are not covered by this brand. The smallest XS to the largest 6XL can go out with protection. When you need to wash your product, this one will be cleaned with ease. It is safe to use in the machine to wash and it will dry well. This is a product that can be used in three seasons, making it very useful for a wide variety of outdoor activities that require a solid base layer.

Cost and Value
This base layer can be pricey but when considering the merino wool material that it is made out of you could make the argument that it could be much more than the price at hand. This is a very durable and quality product that you will get a ton of usage out of. It can support you during so many outdoor activities, if you are a lover of adventure and all things wild, this is a perfect pairing for you. Sizing is vast with smaller sizes to the largest additionally it has to size for taller individuals as well.

2. Darn Tough Vermont Merino Wool

The rating is based on the average rating (1-100) from all the criteria in which we rated this product.
97.3
Darn Tough Vermont Merino Wool
Materials
98
Weight
99
Fit
95
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$26.00
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Pros:

67% Merino Wool, 30% Nylon, 3% Lycra Spandex

Made in the USA

Lifetime Guarantee

High-density knitting

Performance fit

Cons:

If you stretch them out it is harder for them to retain their original fit

A company that lives and works in the state of Vermont, USA. This is where the Darn Tough Vermont Merino Wool sock is made. This is a performance-based sock that is going to serve you well if you enjoy skiing, snowboarding, hiking, biking, and running in the most extreme climates and environments.

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Great Socks
These socks made of mostly merino wool are very comfortable on the skin and are very soft. They differ greatly in that respect, from others on the markets that are made out of cheap synthetic fibers. Your feet will be able to maintain a nice internal temperature without excessive sweating, they can keep you warm in boots without the added bulk that you will often see in the construction of others on the market. They fit very well and can stand up to daily use.

Excellently Constructed
The construction of these socks really pays attention to the details. They will stay up over your calves and they stay put. They don't scrunch up and slide down easily, they aren’t itchy, and they are super warm. There is additional padding in the heel, toe, and shin area so that those high impact areas have extra protection and provide additional comfort.

Cost and Value
Worth every penny if you are a hiker or climber, you will not be disappointed. They stay put, they are soft, they have added features to increase comfort and fit. They provide terrific temperature regulation and the fact that they are a tall sock, they cover a good portion of the lower leg. Even if you are out in the cold, at some point if you are engaging in a physical activity you are going to sweat, these will naturally wick away the sweat keeping your skin nice and dry.

3. J.B. Extreme - 30t

The rating is based on the average rating (1-100) from all the criteria in which we rated this product.
96.7
J.B. Extreme - 30t
Materials
97
Weight
98
Fit
95
best offer for today
Pros:

7 color options

No-Risk Guarantee

Air-vent and Protect Guard to keep foul odors at bay and keep them free of bacteria

Breathable and moisture wicking

Spandex keeps this sock in place

Nylon on the outside gives them a rugged durability

Cons:

Buy a size or two bigger, then wash in hot water so they shrink to your intended size

This technical sock will hold up and be a reliable companion in the most frigid conditions. J.B. Extreme - 30t is made with 70% Merino wool, 25% nylon, and 5% Spandex, this sock is 12” in length and it is manufactured in Canada.

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Great Comfort
The foot and leg are made with a pleasing terry knit that provides you with a good lifespan, and a reliable amount of wear and durability. The spandex will help keep this sock from sliding and is strategically placed in the arch and the ankle areas. The outside construction makes use of durable and tough nylon so that it can stand up to wear and tear. Treated with ProtectGuard as well as Air-vent you will have a healthy sock clear of microbial and foul odors while excessive heat and moisture will be flushed out for a very cozy and enjoyable fit. a.

Quality Guarantee
The no-risk guarantee that comes with this product will give you plenty of peace of mind. This is a company that believes in their product and their construction so much that they will offer a solid backing and provide you a tremendous amount of supportive customer service if you ever need to be in touch with them.

Cost and Value
There are 7 color options to choose from which gives them some variability in appearance. The price is very appealing given the details included in the design, construction, and use of materials in this sock. These are going to keep you warm and keep your foot health.

4. Carhartt Base Force

The rating is based on the average rating (1-100) from all the criteria in which we rated this product.
95.7
 Carhartt Base Force
Materials
97
Weight
95
Fit
95
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Pros:

A very warm base layer that actually gets softer with a couple washes

Has stain breaker technology to allow washers to lift smudges from the fibers of the textile with ease

Rib-knit cuffs at the bottoms keep in warmth

Elastic waistband is comfortable, reduces sliding, and makes a secure seal

Cons:

Can be pricey

When anyone says Carhartt the basic response is rugged, durable, tough, and strong. This is the brand for those that work out in the elements, early morning to late night and need clothing that is going to keep them insulated and protected. No doubt the Carhartt Base Force is going to not only retain heat, but it will also be heavy-duty.

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Tough
Made with 9.5 ounces, 100 percent cotton ring-spun knit that will remove any sweat away from your skin so that you aren’t bogged down with cold moistness that chills you to the bones. The maintenance is a breeze with the stain breaker technology that allows this to be effectively cleaned in the washer by having any stains or other smudges simply release themselves from the material fibers. Extra tough reinforced stitching keeps these together like armor.

Look Confident
Wear this base layer proudly as the Carhartt and force logos will be visible. The rib-knit cuffs keep a snug fit to the ankles so that all your heat can be maintained inside. The elastic-like top will also keep these snug to your waist so they will stay up and not slide and this area will also seal in the warmth you need in frosty conditions.

Cost and Value
Carhartt is just a solid company that makes amazing outdoors gear. Their biggest claim to fame is their heavy-duty coats, these things will last literally a lifetime, they can go through a hurricane and still maintain their integrity. This same type of design and construction is used in all their products including their base layers. This brand services those who have to face the most extreme elements and they make products that will stand up to those elements and keep their customers comfortable. They are moderately priced, but you aren’t going to get this type of quality on the cheap.

5. ColdPruf

The rating is based on the average rating (1-100) from all the criteria in which we rated this product.
95
ColdPruf
Materials
95
Weight
96
Fit
94
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Pros:

100% polyester

Cotton two-layer engineering for extreme warmth

Sits on the natural waistline

Tagless labeling for a more comfortable fit

Best for very cold weather with low to medium activity levels

Moisture-wicking abilities

Green business initiatives

Affordable

Cons:

The stitching can be a bit less flexible and stretchy than the rest of the material which is awkward

Seams may cause irritation in the inner part of the leg, where the skin is more delicate

ColdPruf is a base layer that will keep you warm and provide essential mobility so that you can engage in outdoor activities without a problem. The technical fibers used have the Silvadur Intelligent system which keeps your pants fresh, odor-free, and reduces harmful and unhealthy bacteria from developing and growing on the fabric.

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Warmth Technology
The cotton two-layer engineering is really something. It is set up to trap your natural body heat between the layers. You effectively act as your own furnace. This allows the outer portion of the pant to shield from the cold while the inner portion is circulating warm air. The polyester textile will do it’s magic keeping the pant very strong, almost tear resistant, and will help it hold its shape as it isn’t a fabric that is prone to shrinkage.

Cozy and Comfortable
The tagless labeling is a thoughtful feature that will allow this product to sit well on your body without any annoying itching or irritation from a flapping piece of fabric. The front and back rise gives a great amount of coverage and very smooth wearing when you are engaged in outdoor activity. The front fly is another practical feature.

Cost and Value
Crunchy granolas or those who appreciate companies that have a green focus in their business structure will like this brand because it isn’t extravagant in price, it is very affordable. It is also very sustainable in production. This is a company that emphasizes recycling, reusing materials, maximizing energy output and leaving as little waste with every process they engage in as possible.

6. First Lite Allegheny

The rating is based on the average rating (1-100) from all the criteria in which we rated this product.
94
First Lite Allegheny
Materials
94
Weight
95
Fit
93
best offer for today
Pros:

Made in the USA

18.5 micron, Superfine, Pure 100% Merino Wool

Contains heat in wet and dry environments

Easy to clean and can dry well

Can last for extended periods of time without developing a foul odor

Cons:

Not made to be put into the dryer

The fit is not skin tight

First Lite Allegheny fits true to size so whatever your natural body size is would be what you’d want to purchase and then it will layer on nicely beneath your clothing. The use of Merino wool in the fiber mix is a nice compliment which will naturally keep you comfortable in all extreme temperatures, those that are very high and the lowest and coldest.

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Can Last For Days
A very important feature about this product especially for those that are going out in the wilderness for some time and need to pack light, pack smart, and not have access to amenities for some time, these are going to serve you well. They can actually last for a couple of days on without developing a build-up of odor making yourself a bit too ‘ripe’ for others or yourself. In addition, if you find yourself sweating, these won’t keep that moisture in making your skin clammy, they will wick it away and dry quickly so you can maintain a comfortable feel and dryness that will aid in containing essential warmth.

Rejuvenate your Grip
Laundering your pants is easy, and that is when you need to. These can last for a bit before you will need to give them a good cleaning. When it is time, however, you it is not a complicated task and these will dry out well on their own making them ready for your next outing.

Cost and Value
This Is a product that will move with you, handle the elements, and legit keep you set with temperature regulation and comfort for days should you need to use them on a long term basis like that. This makes these an ideal pair for hunters or especially for through hikers that go on long hikes with stops for quick camps where packing light and effectively is most essential. They are very pricey but when you consider the amount of use you will get out of them and the tremendous support they will provide you on a reliable resistant basis, it is definitely worth it. Those who need to pack smart will get their money’s worth with this base layer pant.

7. Icebreaker Merino Everyday

The rating is based on the average rating (1-100) from all the criteria in which we rated this product.
92.7
Icebreaker Merino Everyday
Materials
92
Weight
93
Fit
93
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Pros:

100% Wool

Fly has a gusset that helps with movement

There is no center back seam in construction

Naturally odor-resistant

Flatlock seams

Breathable and will rid moisture

Cons:

Can have durability issues with tears at the bottom

Leggings can ride up underneath clothing

These leggings have a ton of natural movement built in, the Icebreaker Merino Everyday is made with merino wool just as their name suggests. That makes them odor-resistant and breathable. The gusset helps with better movement and the flatlock stitching won't irritate your skin or annoy you when wearing.

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Movement Friendly
These are light and very breathable using 200gm of pure merino rib fabric. These can be used for every type of activity where extra warmth or temperature regulation is needed. They can be used when working outdoors professionally, hiking, hunting, or camping, they are multi-versatile in what they can accomplish. They have ease of movement as well so they will allow you to climb or crawl or move in whatever way you need.

Non-irritating
The gusset allows for spare room in your joints so that you can stretch and maneuver readily. The design, integrating a flatlock seam will help to minimize, even eliminate irritation and chafing on your skin. A waistband is also smooth to the touch on the skin and also adds to minimal irritability and tenderness that could cause you to be less likely to enjoy this product.

Cost and Value
These are pricey, no doubt, but they have a design that won’t cause extra irritation on your skin. Merino wool is naturally soft to the touch and has a ton of great qualities for a base layer material.

8. Tasc Performance

The rating is based on the average rating (1-100) from all the criteria in which we rated this product.
90
Tasc Performance
Materials
92
Weight
88
Fit
90
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Pros:

55% organic cotton, 40% viscose from bamboo, and 5% elastane

Moisture wicking

Mesh ventilation

UPF 50+ protection

Machine washable

4-way stretch

Raglan seaming helps with movement

Fits true to size

Cons:

The collar can be on the smaller size especially if you are of a muscular build

A perfect pairing made popular by athletes, Tasc Performance is a top that will contour to the body with a skin with a tight fit. It will alleviate chafing, you won’t even feel like you have it on.

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Second Skin Fit
This top fits like a second skin so it will easily fit as a base layer under pretty much any type of clothing. Even though it provides a close fit it doesn’t feel restrictive at all. It also has plenty of stretches so you will have no problem with the range of motion or movement. This is a very soft to that has excellent moisture wicking abilities.

Overall a Great Mitt
This shirt is light but still makes an ideal under layer for those cold days. The coldest days to the best with layers, and having a layer that will lay on the skin without sliding or bunching up and one that won’t add extra bulk makes it a great product that will work with almost any top clothing. The breathability will help your skin stay dry and also keep in the warmth close to your skin.

Cost and Value
For a performance top that can allow you to be extra active this product is priced in the mid-range. It fits under everything and is so light and flexible its like you aren’t even wearing the layer.

9. Columbia Midweight

The rating is based on the average rating (1-100) from all the criteria in which we rated this product.
86.7
Columbia Midweight
Materials
87
Weight
85
Fit
88
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Pros:

100% Polyester

4-way comfort stretch

Antimicrobial treated fabric

Ergonomic seaming

Flatlocked construction

Thermal wear for warmth

Cons:

Moisture-wicking abilities aren’t the best on the market, some may feel a slight stickiness

The Columbia Midweight top is comfortable midweight layer gives just enough thickness without being overly bulky. It will stay put under other layers and it has breathable, stretchy, and moisture wicking abilities that make it very versatile to wear as a base.

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Great Athletic Top
This is a great product of the most active people who enjoy exercising outdoors in all weather, even extreme cold. Runners, hikers, rock climbers, and the avid skier can gain a lot of heat with the heat entrapment technology this top provides.

Freshness
Omni-HEat thermal reflective lining incorporated into the fabric increases overall warmth you can retain throughout the body. It is a versatile product that works very well on its own or as a layer underneath other clothing. The fabric is treated with anti-odor technology to keep you fresh.

Cost and Value
You will spend a couple of bucks on this top but it has an incredible ability to retain heat, which is what you want on chilly days. It can work well for an average workout as well as benefit you on the slopes. It is a great piece of clothing to have in your closet that you can use whenever you will be in cooler temperatures.

10. Duofold Heavyweight

The rating is based on the average rating (1-100) from all the criteria in which we rated this product.
87.3
Duofold Heavyweight
Materials
87
Weight
89
Fit
86
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Pros:

96% polyester, 4% Spandex Bi-Polyester

Machine washable

Droptail hem

Flatlock seaming

Tagless

Four-way stretch with moisture control

Cons:

Sleeves run shorter

Sizing runs smaller

The Duofold Heavyweight is a top that provides considerable warmth. This is a double layered product that will be your best friend in extremely frigid temperatures.

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Protection
The design of this product will trap warmth between the double layers for maximum heat retention. The dual layers are held together through a knit bond that allows them to form a solid layer that acts as a thermal blockade keeping the cold out.

Features
This top has all the features you would want in performance, thermal top. It is antimicrobial which keeps the integrity of the fabric healthy and reduces bad smelling odors. It is tag-free along with the flatlock seams these features work together to make the fit and feel on your skin less irritation. The four-way stretch allows for maximum mobility and range of motion making this a great sports shirt. It is a solid option for skiing, snowboarding, ice skating, running, hiking, cycling, or mountain climbing in the extreme frigid outdoors.

Cost and Value
This is a moderately priced shirt for a heavyweight model. It is going to work really well for snow bunnies who want to spend the day in the winter wonderland.

Criteria Used for Evaluation

Materials

It is quite possibly very accurate to say that the fabric your thermal wear is made of could be the most important choice you have for picking the perfect layering clothes. Moisture-wicking abilities or the capacity to move wetness away from your skin and keep both your skin and the fabric dry is going to be key. Wet, damp skin in extreme cold is not a good combination. The clothes that are specifically designed to be base layers, and labeled as such will most likely have moisture wicking abilities. Some will be better than others, but at the very least, they should have some capability to rid wetness. To better inform you of the types of fabrics you will come into contact with when looking for a specialized product like this here is a list and some information about how these different fabrics work and what they offer.

Synthetics
When it comes to chemically engineered textiles, polyester is a synthetic material that is commonly used in activewear. Other strong blended fabrics you may encounter include nylon, polypropylene and/or rayon, as well as spandex. The spandex fabrics will provide a nice stretchiness that can also have a close and neat fit that is not going to be too tight and compressing. These textiles can give you really fast drying capacities, they tend to offer the dryest feel of any other fabrics used. They are highly durable, they were engineered to be. If you are going to be engaging in a rough sport or one that can have to snag such as rock climbing you are going to want a very strong fabric. Synthetics are the strongest. The finish in the chemical process of making a synthetic involves the use of a finish that will aid in stopping the development of bacterial build-up which can cause funky smells. That being said, this is a fabric that can cause stickiness to build upon the skin if worn for longer periods of time.

Merino Wool
Contrasting popular believe about wool, which for the most part is correct for some varieties, the itchiness factor doesn’t exist with this variety. Merino wool is soft and has ultrafine fibers making it naturally soft to the skin. It is a highly versatile material that can be used alone for its tremendous natural abilities but can also be blended together with other fabrics to achieve specific results in performance. This wool wicks very well, but when it gets very wet, the downside it takes a bit of time to dry out. It is best used as a base under other layers because when used alone, any wear and tear from backpacks or rubbing and snagging will quickly deteriorate the lifespan of the material. If these wool fibers are blended with other synthetics, though that changes the equation because then there is generally more durability for wearing alone. It is a very neat natural fiber that can offer both cooling effects as well as retaining intense warmth. Last, wool has the natural ability to be very resistant to odor-causing bacterias, so it will keep you fresher longer should you have to wear it for a couple of days without laundering.

Silk
It doesn’t seem like this luxurious material would be a performance fabric used for making a base layer, but actually, it is used in low-activity and for easygoing wear. It can provide you with a bit of natural moisture wicking. It is very supple, a lightweight material slipped under other layers feels soft and smooth on the skin especially if your outer layer is itchier or made of fibers that are uncomfortable for the skin it makes a pleasing barrier. While you aren’t going to use silk to run a marathon or do a cross-training session, a low-key fall hike or a night watching a movie in a drive-in, this is a nice material that will provide adequate support. Remember, it is not naturally odor-resistant so it will need to be laundered after every use, and it is a delicate material, so don’t expect to be doing anything rugged in it as its durability is fragile.

Ceramic/Wool
A new, modern technology that is being used is blending wool with ceramic particles specifically for very hot conditions. The ceramic acts to pull in your body’s heat and then dispenses that heat away from the body and the clothing so that your skin stays cool. It is like a vacuum on the body that will suck up the heat and blow it away from you. We will see where this one goes in time with more research and use it may become a common textile option to add to the performance fabric niche.

Weight

When it comes to base layers, there are a couple of considerations to take into account so you can find the best-specialized option to optimize your performance. You always want to take a hard look at what activity you are engaging in and what environment you will be in, what the temperature of that environment will be, how you are to pack your gear, and finally how your body tends to respond to your surroundings and your activities. For this last consideration, there are three levels of weights that base layers will come in. These layers are lightweight, midweight, and heavyweight. If you are a person who always is cold and cannot get yourself warm easily, you are going to want to go with heavier weights as your base layer. Alternatively, if you are an individual who acts as a natural furnace for yourself and everyone around you, you’d probably be more comfortable going a bit lighter. Lightweight layers will be used for at most moderate temperatures to temperatures that are cool, while midweight is specifically for cold temperatures. Heavyweight, of course, is for the most extreme, those temperatures that are below freezing.

Additionally, you may come into contact with “ultralightweight” a.k.a. “featherweight”, these are outlier weights and models. Only a few brands will try to extend their spectrum to the ‘ultra’ category making these garments especially light, or on the reverse, “expedition weight” which makes things especially thick and heavy.

Fit

Fit
These base layers can come in a range of prices from very affordable to the most pricey. The money isn’t so much as important as the functionality is. If you want your layer to be the most effective, especially at removing moisture then it should fit very close to your skin and be in contact with that moisture so it can do what it has been designed to do. It should have a snug fit on your body, it doesn't necessarily need to be a tight or compression level fit, but it should be close to the body. If the fit is too loose the efficiency at which your gear can remove moisture is reduced.

When it comes to base layers that are used in warmer climates and the desired effect is cooling, some models will be most effective when they access your body’s sweat and then they work to spread it over the larger surface area of the garment. When the liquids evaporate they end up cooling that whole area that they were dispersed across which keeps you very comfortable in hot, humid weather.

Expert Interviews & Opinions

Most Important Criteria (According to our experts opinion)
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Materials
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X out Cotton

Try to steer away from cotton, while dealing with extreme cold in case you get wet cotton takes a very long time to get dry. and you don't want to find yourself in that situation.

Other Factors to Consider

Bottom Line

The base layer’s main job and the way it will be most effective for you is to manage moisture buildup. Whether it is distributing the moisture across the body to act in a large scale cooling effect or to pull moisture away from the body and keep it dry so that heat can be retained, moisture management is priority number one. You can play with the amount of heat you retain using some of the heavier weighted products for additional insulation. With heavier models, the middle layer, those products that use a dual design in fabrics which have that middle area available is actually where the heat is kept offering you that thermal lining. This is different than the base layer.

Frequently Asked Questions

q: How does merino wool heat and cool?
a:

Most people know that good wool will keep you nice and toasty all winter long, especially in during those snowy days. But wool is actually a natural 4-season fiber. The natural crimp that wool has in its physical makeup allows it to pull in and lock down dead air, which is a amazing insulator. Not only can it lock in that air for warmth, but it can also block against the cold. It can also hold a lot of moisture within so that that wetness stays away from your skin. Merino, in particular, is a variety that can absorb up to 30% of their dry weight before you will start to feel any wetness they may have encountered. Compare this with synthetics that absorb less than 7%.

When it comes to cooling, this ability for these fibers to store so many liquids within can have a cooling effect because as your body warms in the heat that liquid will evaporate. The resulting air between your skin and these fibers as they go through the evaporation process results in a process that cools that air. The hotter it is, the warmer you get, the more moisture exists, and the more evaporation occurs which causes an increased cooling effect. It is a natural cycle and it is pretty neat how it works when you take a second to think about it.

q: Can merino wool protect skin?
a:

It will protect your precious skin from those harsh sun rays, with most varieties having a UPF of 30+. Many products, including many of those we evaluated on this list, have a rating of 50+ which is pretty incredible.

q: Is merino wool irritating to the skin?
a:

This fiber is actually very smooth and soft, it doesn’t itch as you would think it may like some other varieties of wool do. It is also static resistant due to that fine ability to keep in so much moisture within those fibers. This moisture build up can help alleviate static electricity accumulation and as such, it eliminates the cling that results. Not only does this feel better when wearing, but if you are near flames or sparks, this will be safe against potential flares that could cause the ignition for a fire.

q: How does layering function?
a:

Here is a quick answer to help you get an understanding of what layers mean and how they work to support your outdoor activities.
The Base Layer is the underwear layer, its main essential role is moisture management.
The Middle Layer is the insulating layer, this is the layer that provides thermal heat protection from frigid temperatures.
The Outer Layer also is known as the shell layer is your protective exoskeleton, if you will. It will be the barrier from wind, ran, and the other elements nature can throw at us.

q: What are non breathable shells?
a:

These are outer layers that are generally waterproof or water resistant, and many times they are coated with nylon to make them windproof as well. They are a basic shell that works well alone on rainy days with minimal activity. If you up your exertion level, then you’d want to think about moisture management which would mean this would be best paired with an appropriate base layer.

Sources

  1. Smartwool.com, Merino Wool 101, Ski Clothing ,
  2. Wikipedia, Polyester, Outdoors Outfitters,
  3. REI, Layering Basics, Outdoors Outfitters,