Best Women’s Long Underwear: Tips on Choosing the Best Base Layer to Keep You Warm

Long underwear
Written by Dorothy Tobias

There should be a lot of planning that goes into choosing the best womens long underwear, because it’s not just about warmth. In fact, some long underwear is designed specifically for keeping cool and wicking away sweat.There are a thousand deciding factors when trying to choose exactly what style is perfect for your outdoor adventure, including odor resistance, material, itchiness, temperature regulation, stretch and fit.

There are thankfully great options available for every situation, as well as for every price range. One thing to consider though, is price point tends to be a good indicator for quality and generally the higher the price point goes the longer the lifespan and the better the warranty.

History of Long Johns

It might come as a bit of surprise, but long johns or long underwear have not been around forever. Especially for women. The garment that we would could most closely compare to the thermal base layers we wear today only began manufacture in England in the 17th century.

Their popularity began to rise during the 18th century and they were most common throughout the northern hemisphere during colder months. Their use in warmer applications has become more fashionable as the material and technology improves. The two piece long john that we all know well today was developed in Truro, Nova Scotia, Canada in 1915 by the Standfield garment company.

Why are they sometimes referred to as long johns? There are two trains of thought on this; the first is that the words stem from the french term “longues jambes” meaning long legs. The other idea is that they were named after a notorious fighter, who tended to only wear thermal underwear when he entered into a knife fight. One story is clearly more exciting than the other!


There are a few different options when determining what fabric to choose for your long underwear needs. Some work better than others in wet conditions, some work better during the colder months while others are more of a four season base layer.


Perhaps not as warm as some natural fabrics, synthetic fabrics containing polyester, nylon, or spandex bends still have quite a few important features. Primarily they dry very quickly, and work better in rainy or humid conditions.

They are much smoother, and layer better than some more abrasive wool fabrics. One of the downsides is synthetic fabrics require much more washing than natural fibers because they don’t have odor resistance. Synthetics are also quite a bit cheaper than other options.

Merino Wool

Often preferred above all other fabrics, Merino wool has a lengthy history of use in long underwear and base layers. When comparing synthetic fabrics versus Merino wool blends, the latter is much warmer. When thinner thicknesses are worn wool also offers great temperature regulation during warm weather as well.

It is extremely odor resistant which makes it a great option for use during longer backcountry trips where you might not have the ability to wash on a daily basis. Merino tends to be on the more expensive side of the long underwear market, but its lifespan can be much greater.


Another natural option that works great for winter sports and use during the colder months. Thermal silk underwear is often treated to improve some of its characteristics, such as improving its moisture wicking capability. Silks are also much thinner than some wool fabrics, and therefore layer much better.

Silks are a bit more temperamental than other fabrics, they need to be laundered daily to avoid odor and are more susceptible to abrasion over time. They are also a bit pricier.


Going hand in hand with fabric choice, also goes care options. Not all materials were created equal in terms of how to care for them, and how frequently. Some fabrics definitely require more attention than others.


One of the most difficult to care for fabrics, silk is particularly sensitive. It needs to be washed frequently, so is not good for situations where washing is not readily available. It needs to be hand-washed and hung to dry, with gentle washing detergents. Silk is easily damaged.

Merino Wool

Wool is a bit finicky when it needs to be washed, but thankfully it rarely does. It can go days (if not weeks) between washings because of its natural antibacterial and anti-odor characteristics. It is great for use in the backcountry because of this. Some wools will require hand washing, or other special treatment but nowadays many thermal base layers are machine washable.

Hot water washing and high temperature drying should always be avoided however, because it can lead to shrinkage. Wool is susceptible to moth infestation, and should be properly stored if not in use for long periods.


The easiest materials to deal with in terms of washing, synthetics like polyester and nylon are quick drying and not-fussy. They need to be washed more than wool, but don’t have any major special requirements. To prolong their lifespan, some companies recommend washing inside out and hanging to dry.


One of the most important parts of any clothing choice, is how you want your long underwear to fit. Thermal base layers need to fit much closer than other layers in order to increase their temperature regulation and moisture wicking abilities. Even in warmer conditions where you may want to have looser fitting clothing, they still need to fit relatively close to the body in order to do their job properly.

If clothing is loose fitting in colder situations, it also will not distribute the warmth evenly meaning parts of the body will get much colder than others. Fabric choice will definitely change how the clothing fits, with synthetics or synthetic blends being more form fitting than all-natural options.

One final aspect to consider is what layer you plan to wear on top of it, because some options will be much smoother on the surface allowing for better movement.


Why do you need long underwear? Are you planning on wearing it casually on a daily basis, during short bursts of physical activity such as running, or are you planning an extensive backcountry excursion?

Pin pointing what functional aspects you need to get out of the thermal baselayer will help guide you in deciding what will work best for you in the long run.

  1. Moisture Wicking – Do you expect to use the base layer in warm or humid conditions? Will you sweat a lot during physical activity? Picking underwear that performs better when wet, or dries more quickly can be the difference between a having a miserable or a great experience
  2. Odor Resistance – How much access will you have to a washing machine? How long do you plan on wearing the item before washing and does a build up of odor matter for you?
  3. Stretch – If you are just lounging around, stretch might not be a key factor for you. But if you are planning on climbing a mountain, or trail running, stretch will inevitably become a major decision maker in your long underwear purchase.
  4. Warmth – Thicker material also tends to mean more warmth. How warm do you need to be and for how long? With thicker warmer materials, they also become less layerable, so the amount of layers you are planning on wearing at any given time should also go into your consideration.

Top Women’s Long Underwear Reviews

Ibex Women’s Woolies 2 Crew Shirt

Ibex Merino Wool Women's Woolies

Weight: 14.7 oz

Dimensions: 10 x 5 x 3 inches

Features: Midweight Interlock Fabric, Label Free, Odor resistant, Machine Washable

Best Use: Cycling, Camping, Hiking, Winter Sports, Running

As a base layer, the Ibex Woolies 2 is built to be your foundation for adventure. Are you taking it on an extended dog sledding journey through the Arctic circle? Are you using it to hike for a week straight through the Grand Canyon?

This is the perfect base layer for both extremes, warm or cold this Woolie has your back, literally! It is designed to be a perfect midweight base layer, to wear next to the skin and wick away sweat while regulating your temperature. It’s also designed with a very flattering fit for the female form, and a high crew neck.

Related: Match the top to the bottom with the Ibex Women’s Woolies Bottom. It would be a terrible thing to only keep your upper body warm, and the bottoms come with exactly the same benefits as the top.

Check the price on Amazon

The North Face Women’s Warm Zip Neck

The North Face Women's Warm

Weight: 8 oz

Dimensions: 7 x 12 x 2 inches

Features: Zip Up Front, Synthetic Material, Anti-Odor, Flash-Dry Technology

Best Use: Casual Wear, Skiing, Winter Sports, Everyday

For those looking for something a bit more stylish than the stereotypical merino wool underlayer, the North Face has designed a beautiful half-zippered base layer for wear everyday. It comes in a variety of colours, and can be worn on its own instead of just hiding it under a mid layer.

Because it is made with a combination of synthetic polyesters, it is far more stretchy than other natural fibers making it much more feasible for use in more active sports. The material is also extremely quick to dry, and keeps sweat induced odors at bay.

Related: Looking to keep warm and stylish this Winter? Get The North Face Thermoball Cardigan as a fashionable outer layer to use in conjunction with the base layer.

Check the price on Amazon

Kari Traa Vrang Long Underwear Top

Kari Traa Vrang Long Underwear Top

Weight: 14.7 oz

Dimensions: N/A

Features: Delicate Pattern, Stretchy Fabric, Odor Resistant, Moisture Wicking

Best Use: Winter Sports, Alpine, Mountaineering

Base layers seem to always been boring, black, navy and bland. The Kari Traa base layer takes long underwear design to an entirely new level through their Vrang line. The line is made out of a combination of merino wool and modal, which adds a bit of stretch to a fabric that typically doesn’t have any. It has a very beautiful aesthetic, with delicate patterns and contrasting seam colouring.

It also comes in a wide variety of colour options. It’s so beautiful that it can be worn as a top without you ever hitting the ski hill. However, it’s so warm that it has been compared to a furnace, and therefore makes an exceptional base layer for those actively pursuing deep powder and high peaks in the middle of winter.

Related: With a top that looks so good, you literally have to get the entire outfit. This includes matching Kari Traa socks and Kari Traa bottoms, which will make you the envy of everyone at the ski lodge.

Check the price on Amazon

SmartWool NTS Midweight Base Layer Top

Smartwool Women's NTS

Weight: 7.2 oz

Dimensions: 9 x 7 x 1 in

Features: Smart Seam Technology, Odor Resistant, Moisture Wicking

Best Use: Winter Sports, Running, Cycling, Hiking

Smartwool NTS Midweight Crew baselayers are a standard in the long underwear industry. They have been around for decades perfecting the technology around staying warm and dry. This newest midweight base layer has taken a close look at how seams can affect performance.

The top has smart seam technology, meaning there is no shoulder seam, instead it has wrapped around the front. It also has been built using flatlock seams, reducing the risk of chafing even more. Finally the merino wool is exceptionally soft, in comparison to other wool base layers. If you are prone to getting itchy, or chafed by your base layers this SmartWool was designed with you in mind.

Related: Considering you are most likely to lose body heat through your head, adding a SmartWool Merino Wool Cuffed hat to your order will lock in all that heat being managed by your baselayer.

Check the price on Amazon

Columbia Midweight II Long Sleeve Top Shirt

Columbia Midweight II Long Sleeve Top Shirt

Weight: 7.8 oz

Dimensions: 9 x 6 x 3 in

Features: Thermal Reflective Technology, Moisture Wicking, Synthetic Fabrics

Best Use: Commuting, Running, Urban Winter Sports

If wool makes you itchy, switching to a Columbia Midweight thermal could be a perfect solution. Made entirely out of synthetic fabrics, mainly polyester, it is smooth and slides easily over rubbing points like around the neck, underarms, and around elbows.

It also has a disco-ball like interior, which is Columbia’s patented Thermal Reflective technology. This keeps warm air trapped inside, keeping you warmer for longer. Despite being made out of polyester it does still keep you dry even throughout strenuous activity.  Thankfully, it’s also breathable, form fitting and flexible to your specific needs.

Check the price on Amazon

Patagonia Capilene Thermal Weight Bottoms

Patagonia Capilene Thermal Weight Bottoms

Weight: 12.5 oz

Dimensions: N/A

Features: Breathable, Moisture Wicking, Stretchy, Built for Layering

Best Use: Backcountry, Alpine, Winter Sports

Okay, enough about the topside, let’s focus now on a great pair of warm, cozy bottoms to keep you and your bottom comfortable in the backcountry. These Patagonia Capilene bottoms focus on being the perfect base layer, smooth, thin yet still extremely warm. For most people, they keep these on 24 hours a day on multi day backcountry trips.

They offer great moisture wicking technology during strenuous activity, but also are a great thermal for the night. Keeping to Patagonia’s commitment to social justice and the environment, they are also a bluesign approved design meaning the fabric comes from factories that have high environmental standards. They also come from Fair-Trade certified factories, where workers are given a fair wage and fair treatment.

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Icebreaker Long Sleeve Crew for Women

ICEBREAKER Women's Everyday Lightweight Crew

Weight: 8 oz

Dimensions: 11 x 6 x 2 in

Features: 4 Season Temperature Regulation, Flatlock seams, Odor Resistant

Best Use: All-Sport, Backcountry, Running, Cycling

Very lightweight, and very comfortable; a perfect base layer to pull on before heading out for a long day of outdoor adventure. Because Icebreaker Everyday Long Sleeve is so lightweight it is also a great option for summer time activity, after all Merino wool is great for keeping odor down, and moisture low.

Its specially designed seams also make it great for layering, or during times when you might be wearing a pack. It is soft and supple, with smart seams, so should completely reduce any risk of chafing. Despite the higher price point, the craftsmanship and smart design that goes into each and everyone of Icebreakers products makes it worthwhile.

Related: Although its unlikely, you might think that the Everyday Long Sleeve Crew might not keep you warm enough. If you lean towards the cold side, why not step it up a notch with the Icebreaker Women’s Tech Top Long Sleeve Half Zip Top. It has a mock turtleneck, and thicker Merino Wool fabric to up the thermal capacity even more!

Check the price on Amazon

Long Underwear for All Pursuits

For many outdoor enthusiasts and adventurers, long underwear begins to make its way out from under the layers of sweaters and fleeces to become a fashion statement in and of itself. For many, long underwear is worn for all activities because it is warm, dry and comfortable.

Featured Image Source: “Red Long Johns, California” by peter barwick is licensed under CC BY-NC-ND 2.0


Dorothy Tobias

Dorothy is a full-time writer, who loves traveling, good food, and understands the beauty of a night spent under the stars. She likes to discover new experiences wherever she goes and she feels most comfortable in her tent, with her favorite sleeping bag. Dorothy started camping with her family when she was 4 years old and remained loyal to the practice throughout the years. Today, she is an experienced backpacker and camper and knows everything there is to know about products in this niche.