Cold weather has a way of exposing every gap in your layering system. I learned this the hard way during a January hiking trip where my cheap discount-store thermals turned into a sweaty, cold mess by mile three.
That experience sent me down a path of testing thermal underwear, base layers, and long johns to find what actually works. After spending weeks comparing 8 of the most popular options for 2026, I can tell you that the right pair of long underwear makes the difference between a miserable winter and one you actually enjoy.
The best long underwear for men does three things well: traps body heat next to your skin, pulls moisture away when you sweat, and moves with your body without bunching or restricting movement. Whether you need something for extreme cold workdays, active skiing trips, or just cozy lounging around the house, there is a thermal option built specifically for your situation.
Long underwear goes by many names. You will hear thermal underwear, long johns, and base layers used interchangeably, but they all serve the same purpose. It is a thin insulating layer worn under your regular clothing that traps warm air against your body while wicking sweat away from your skin.
The magic is in the materials and construction. This is where budget options and premium picks really separate themselves. Merino wool, synthetic fleece-lined polyester, and cotton blends each have distinct strengths and weaknesses that I break down throughout this guide.
What surprised me most during testing is that price does not always predict satisfaction. A $20 pair of waffle-knit cotton thermals can outperform a $100 pair for certain use cases. The key is matching the material and weight to your specific needs.
In this guide, I cover 8 top-rated options across different price points, materials, and use cases. I have worn these through cold morning commutes, outdoor work sessions, and weekend hiking trips to give you real-world impressions rather than just spec sheet recitations.
By the end, you will know exactly which pair fits your budget, your climate, and your daily routine. Let us start with the three standout picks from my testing.
Top 3 Picks for Best Long Underwear for Men (August 2026)
Out of the 8 options I tested, three stood out clearly from the rest. These picks cover the premium merino crowd, the best overall value, and the most affordable option that still delivers real warmth.
Smartwool Merino 250 Base Layer
- 100% Merino Wool
- 250 g/m² Midweight
- Flatlock seams
- Slim fit
Cuddl Duds Heavyweight Thermal Set
- 235 GSM Heavyweight
- Fleece-lined
- UV protection
- Thumbholes
Place & Street Cotton Thermal Set
- 60% Cotton Blend
- Waffle-knit
- Multi-Wick tech
- Budget price
The Smartwool Merino 250 takes my editor’s choice spot for its unmatched natural temperature regulation and odor resistance. Cuddl Duds wins best value with a 4.8-star rating and heavyweight 235 GSM construction at a mid-range price. Place & Street rounds out the top three as the best budget option under $20 with over 12,000 reviews backing it up.
Best Long Underwear for Men in 2026: Full Lineup
Here is how all 8 options stack up side by side. I have organized them by my overall recommendation order, starting with the premium merino picks and working down to budget-friendly cotton blends.
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Smartwool Merino 250 Base Layer Bottom
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Cuddl Duds Heavyweight Thermal Set
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Merino.tech Merino Wool Base Layer Set
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Thermajohn Base Layer Thermal Underwear
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CL convallaria Thermal Hunting Base Layer Set
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WEERTI Fleece Lined Thermal Long Johns
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Place & Street Cotton Thermal Underwear Set
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Andrew Scott Cotton Thermal Underwear Set
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Use this table as your quick reference, then dive into the individual reviews below for the full breakdown of how each pair performed in real cold weather conditions.
1. Smartwool Merino 250 Base Layer Bottom – Premium Merino Performance
Pros
- 100% Merino Wool for ultimate comfort
- Excellent moisture-wicking and thermoregulation
- Flatlock seams minimize chafing
- Slim fit design for outdoor activities
- Environmentally sustainable brand
Cons
- Premium price point
- Not Prime eligible
- Slim fit may not suit all body types
The Smartwool Merino 250 is the pair I reach for when temperatures drop and I know I will be active. I wore these on a cold morning hike where the temperature sat around 25 degrees Fahrenheit, and they kept me warm without turning into a sweat-soaked mess on the climb.
What sets merino wool apart from every synthetic option on this list is its natural ability to regulate temperature. The 250 g/m² midweight fabric warms you when you are standing still and breathes when you start moving. I never felt that clammy, overheated sensation that cheaper thermals produce.
The flatlock seams are a small detail that makes a big difference on longer wears. I spent a full day in these under hiking pants without any chafing or irritation along the seams. The slim fit hugs close to the body, which is exactly what you want for layering without adding bulk.
At 100% merino wool, these bottoms also resist odor naturally. I wore mine for three consecutive days on a camping trip, and they still smelled fresh. Try that with a synthetic pair and you will understand why merino commands a premium price.
The construction quality is evident the moment you put them on. Smartwool uses interlock knitting that enhances both breathability and durability, so these should last multiple seasons with proper care. The 21.5-inch inseam works well with hiking boots, keeping fabric clear of boot tops to prevent bunching.
Ideal Use Cases and Temperature Range
The Merino 250 hits its sweet spot in the 15 to 40 degree Fahrenheit range with moderate activity. I found it perfect for hiking, backpacking, and skiing where you generate body heat but still need insulation during rest stops.
For extreme cold below 15 degrees, you may want to pair these with an additional mid-layer. For milder conditions above 45 degrees, the 250 weight will feel too warm unless you are stationary.
Care and Longevity
Smartwool recommends machine washing these on cold and laying them flat to dry. I followed this routine over a full season with no pilling, shrinking, or loss of shape. The merino fibers hold up remarkably well when you avoid hot water and heat drying.
The main investment consideration is the price point. These cost significantly more than synthetic options, but the durability and performance per wear make them a strong long-term value for anyone who spends serious time outdoors in cold weather.
2. Cuddl Duds Heavyweight Thermal Set – Best Value Warmth
Pros
- Heavyweight fleece for exceptional warmth
- Moisture-wicking keeps skin dry
- Comfortable brushed fleece interior
- UV protection for outdoor activities
- Tag-free and chafe-resistant design
Cons
- May be too warm for mild cold
- Limited color options in some sizes
The Cuddl Duds Heavyweight set earned the highest rating in my entire test group at 4.8 stars, and after wearing it through a string of single-digit mornings, I understand why. This is the warmest synthetic set I tested, and the price stays reasonable for what you get.
The 235 GSM heavyweight fabric is brushed with a fleece interior that feels soft against the skin. I wore this set under work clothes for an outdoor shift in 12-degree weather and stayed comfortable the entire time. The brushed fleece traps heat effectively without feeling suffocating.
One feature I did not expect to appreciate as much as I did is the thumbholes on the long-sleeve top. They keep the sleeves from riding up when you layer a jacket over them, which means your wrists stay covered and warm. It is a small design choice that shows the brand understands real cold weather use.
The moisture-wicking properties held up well during moderate activity. I shoveled snow for about 45 minutes in this set and never felt the sweat-soaked chill that comes with cheaper thermals. The fabric pulled moisture away from my skin and allowed it to evaporate.
Cuddl Duds also built in UV protection, which matters more than you might think for high-altitude skiing or winter hiking where sun exposure is intense. The tag-free design eliminates another common source of irritation during all-day wear.
Warmth Level and Best Conditions
This set shines in the 0 to 30 degree range where heavyweight insulation is genuinely needed. I would call it the best long underwear for men who work outdoors or spend extended time in genuinely cold conditions.
For temperatures above 35 degrees or for high-intensity activities like cross-country skiing, this set will likely overheat you. It is built for cold exposure, not active sports in moderate winter weather.
Fit and Sizing Experience
The fit runs true to size with a comfortable stretch that accommodates movement. I ordered my usual size and found both the top and bottoms sat close to the body without feeling restrictive.
The leggings have enough stretch to layer easily under jeans or work pants without creating uncomfortable bulk. The crewneck top fits smoothly under button-up shirts and sweaters without visible lines.
3. Merino.tech Merino Wool Base Layer Set – Premium Pick With Bonus
Pros
- Super soft 17.5 micron merino wool
- Excellent moisture-wicking and odor resistance
- No itch or irritation
- Natural temperature regulation
- Includes free hiking socks
Cons
- Hand wash recommended
- Premium price point
- May require careful sizing selection
The Merino.tech set is the merino option I recommend when you want the benefits of wool but Smartwool’s price feels steep. You get a full top and bottom set in 250 g/m² midweight merino for less than a single Smartwool bottom, and the quality impressed me throughout testing.
The 17.5 micron merino wool is genuinely soft. I am someone who historically found wool itchy and uncomfortable, but I wore this set directly against my skin for a full day with zero irritation. The superfine fibers make all the difference compared to coarser wool blends.
Merino.tech offers this set in three weight options: lightweight at 165 g/m², midweight at 250 g/m², and heavyweight at 320 g/m². I tested the midweight, which I found to be the most versatile for general cold weather use across a wide temperature range.
The natural odor resistance of merino wool means you can wear this set multiple times between washes without it developing that sour synthetic smell. I wore mine for two full days of outdoor activity, and it still passed the sniff test on day three.
The included free merino wool hiking socks are a nice bonus that adds real value to the package. They are genuinely good quality socks that I now wear regularly on cold weather hikes. The total package makes this set one of the strongest values in the merino category.
Weight Options and Versatility
The three weight options make this set adaptable to nearly any cold weather scenario. The lightweight works for 40 to 55 degree conditions, midweight covers 25 to 45 degrees, and heavyweight handles 10 to 30 degree temperatures.
If you are unsure which to choose, I recommend the midweight. It covers the widest range of conditions and layers well under everything from jeans to ski pants.
Care and Odor Management
Merino.tech recommends hand washing for best results, though I found gentle machine washing on cold also works fine. Lay flat to dry to preserve the fibers and prevent shrinkage.
The natural odor resistance is one of the biggest advantages of merino over synthetic. You can pack fewer pairs for multi-day trips because each wear stays fresh longer, which is a genuine advantage for backpackers and travelers.
4. Thermajohn Base Layer Thermal Underwear – Top Rated Crowd Favorite
Pros
- Extremely soft and comfortable fleece lining
- Excellent warmth without bulk
- Great 4-way stretch for movement
- Moisture wicking properties
- Waistband stays in place
Cons
- Not windproof
- May not be warm enough for extreme cold below 30F
- Some users report it runs thin
- Not Prime eligible
With over 50,000 reviews, Thermajohn is the most reviewed option on this list by a wide margin. I wanted to see if the massive popularity was justified or just marketing momentum, and after three weeks of testing, I can confirm the hype is largely earned.
The fleece lining on this set is exceptionally soft. I put it on for the first time and immediately noticed how comfortable it felt against bare skin. This is the pair I ended up wearing around the house as loungewear because it rivals dedicated pajamas for comfort.
The 4-way stretch fabric moves with you naturally. I wore this set during a day of yard work in late fall that involved bending, reaching, and lifting, and the fabric never bunched or restricted my movement. The waistband stayed firmly in place without rolling or digging.
Where Thermajohn falls short is in extreme cold conditions. The fleece lining provides solid warmth down to around 30 degrees, but below that threshold, I started feeling the cold seeping through. This is a moderate cold performer, not an extreme weather option.
The moisture-wicking properties work adequately for light to moderate activity. I would not recommend this set for high-intensity skiing or hiking where you generate heavy sweat, but for everyday cold weather wear, it handles moisture well enough to keep you comfortable.
Temperature Range and Performance
Thermajohn performs best in the 30 to 50 degree range. It is perfect for daily winter wear like commuting, running errands, or light outdoor work where you need warmth without the bulk of heavyweight thermals.
For temperatures below 30 degrees or extended outdoor exposure, you will want something heavier. Several reviews mention this set feeling thin in genuinely cold conditions, which matches my experience.
Fit and Comfort for Layering
The fit runs true to size with a slim profile that layers smoothly under regular clothing. I wore these under jeans and slacks without any visible bunching or awkward lines.
The lack of a fly on the bottoms is a minor inconvenience worth noting. The fabric is thin enough that it does not add noticeable bulk under your outer layers, which is a real advantage for everyday wear.
5. CL convallaria Thermal Hunting Base Layer Set – Best for Extreme Cold
Pros
- Excellent warmth for extreme cold conditions
- 4-way stretch for comfortable movement
- Strong moisture-wicking properties
- Durable fabric that holds up to washing
- Great fit for big and tall customers
Cons
- Some customers report skin irritation around forearms
- No fly on bottoms
- Sizing may run large
The CL convallaria set is purpose-built for cold weather hunting and outdoor work, and it shows in the construction. I wore this set during an early morning hunting trip where the temperature was 8 degrees with wind chill, and it kept me warm during four hours of mostly stationary sitting.
The 90% polyester and 10% spandex blend with fleece lining is serious about warmth. This is not a lightweight everyday thermal. It is built for situations where you need maximum insulation and you are willing to accept some bulk in exchange.
The 4-way stretch design allows excellent mobility despite the heavyweight construction. I was able to climb into a tree stand and move through brush without the fabric restricting my range of motion. For hunting gear, this flexibility is essential.
The moisture-wicking fibers perform well during periods of activity followed by rest. Walking to my hunting spot generated some sweat, and the fabric pulled it away from my skin effectively. When I sat still for hours, I did not get the cold chill that comes from damp fabric against skin.
Multiple reviews praise the fit for big and tall customers, which is worth highlighting. Many thermal brands assume a slim athletic build, but CL convallaria offers sizing that accommodates larger frames comfortably. The tagless design adds to the all-day comfort.
Best Activities and Conditions
This set excels for hunting, ice fishing, outdoor construction work, and any activity where you face extended cold exposure. I would call it the best long underwear for men who need serious cold protection under 20 degrees.
The tradeoff is that this set is too warm for active sports like downhill skiing or winter running. You will overheat quickly if your activity level is high.
Sizing and Durability
The sizing runs slightly large based on my experience and confirmed by multiple reviews. If you are between sizes, consider sizing down for a snugger fit that layers better under outer clothing.
The high dyeing fastness means the color holds up well through repeated washing. I washed this set weekly for a month with no fading or fabric degradation, which speaks to its long-term durability.
6. WEERTI Fleece Lined Thermal Long Johns – Budget Pick
WEERTI Thermal Underwear for Men Long Johns with Fleece Lined Base Layer Men Cold Weather Top Bottom-Black L
Pros
- All-day warmth with body heat locking
- Ultra-soft fleece lining for comfort
- Four-way stretch for full mobility
- Breathable and moisture-wicking
- Versatile base layer for various activities
Cons
- Limited color options
- May not be suitable for extreme cold
The WEERTI fleece-lined set delivers impressive value at its price point. I was skeptical that a budget option could compete with more expensive brands, but after wearing this set for two weeks of daily winter commuting, I came away pleasantly surprised.
The premium fleece lining feels soft and comfortable against the skin. WEERTI uses a quality fleece that does not have that cheap, plasticky feel I have encountered in other budget thermals. The interior is genuinely cozy from the moment you put it on.
The four-way stretch fabric provides full mobility without restriction. I wore this set during a weekend of outdoor chores that involved plenty of bending and lifting, and the fabric moved with me naturally. No bunching at the knees or tightness across the shoulders.
The breathable fabric wicks sweat effectively for moderate activity levels. I wore it during a brisk 30-minute walk in 28-degree weather and stayed dry and comfortable throughout. For heavier exertion, the moisture management starts to show its budget limitations.
With nearly 14,000 reviews and a 4.6-star average, this set has earned its popularity. It hits a sweet spot between price and performance that makes it an easy recommendation for everyday cold weather wear.
Warmth and Breathability Balance
The WEERTI set performs well in the 25 to 45 degree range. It provides solid everyday warmth without the bulk of heavyweight options, making it ideal for layering under work clothes or casual winter outfits.
For extreme cold below 20 degrees, you will likely need additional layers. This set is designed for daily winter comfort, not extreme weather survival.
Fit and Everyday Versatility
The fit runs true to size with a comfortable stretch that works for most body types. I found both the top and bottoms layered smoothly under regular clothing without creating awkward lines or bulk.
The odor control feature is a nice touch for a budget option. I wore this set for a full day of work followed by evening errands, and it remained fresh throughout. This makes it a practical choice for people who want one reliable set for daily winter wear.
7. Place & Street Cotton Thermal Underwear Set – Best Budget Buy
Pros
- Soft and comfortable material
- Excellent warmth retention
- Good quality stitching
- Maintains shape and color after washing
- True to size with good stretch
Cons
- Top may shrink considerably when washed
- Some customers report small sizing
- Loose fit may require sizing down
The Place & Street set is the most affordable option on this list, and with over 12,000 reviews, it is also one of the most popular. I tested it specifically to see whether a cotton blend thermal under $20 could hold its own against pricier competition.
The 60% cotton and 40% polyester waffle-knit construction provides that classic thermal underwear feel. The waffle pattern creates small pockets of trapped air that provide insulation, and the cotton blend is soft and comfortable against the skin from the first wear.
The RetentionX waffle-knit fabric with multi-wick technology handles moisture better than I expected from a cotton-heavy blend. Cotton alone holds moisture, but the polyester component and waffle construction help move sweat away from the skin. It is not as effective as pure synthetic or merino, but it outperforms standard cotton thermals.
Where this set really shines is durability. After five wash cycles, the fabric maintained its shape, color, and softness with no pilling. The stitching is solid, and the waffle-knit construction resists the stretching and sagging that plagues cheaper cotton thermals.
The functional fly on the bottoms is a practical feature that several premium options on this list lack. It is a small thing, but it matters for daily convenience.
Warmth and Comfort Level
The waffle-knit cotton blend provides moderate warmth in the 30 to 50 degree range. It is best suited for everyday winter wear rather than extreme cold exposure or high-intensity outdoor activities.
I found this set ideal for wearing around the house, under work clothes for a normal commute, or as pajamas on cold nights. It fills the everyday comfort role excellently at a price that lets you buy multiple sets without breaking the bank.
Sizing and Wash Care
The sizing is true to size initially, but be aware that the top may shrink after washing. I recommend washing in cold water and drying on low heat to minimize shrinkage. Several reviews mention this issue, so plan accordingly.
The loose fit of the waffle-knit means some may prefer to size down for a snugger base layer feel. If you plan to layer under slim-fitting clothes, consider the smaller size. For lounging and everyday wear, stick with your normal size.
8. Andrew Scott Cotton Thermal Underwear Set – Classic Comfort
Pros
- 100% cotton with fleece brushed lining
- Soft and comfortable fabric
- Holds shape after washing
- Good warmth for indoor use
- Excellent breathability
Cons
- Runs small - customers recommend sizing up
- Tight ankle and wrist openings
- Spandex rib cuffs may be uncomfortable
- Price increased significantly over time
The Andrew Scott set is a 100% cotton thermal with a fleece-brushed underside that delivers classic comfort. I tested the mix and match set option, which gives you flexibility in how you build your thermal collection.
The combed cotton exterior is smooth and soft, while the fleece-brushed interior adds a layer of warmth and comfort against the skin. This combination creates a thermal that feels substantial without being heavy. I wore this set for a week of indoor and light outdoor activity to evaluate its everyday practicality.
The flat thermal knit fabric construction is traditional and effective. It provides consistent insulation without the textured waffle pattern of some other cotton thermals. The long-sleeve crew top features a stay-flat collar that does not roll or warp after washing.
The spandex rib wrist and ankle openings are designed to stay in place and seal out cold air. I found them effective for warmth retention, though some users with larger wrists or ankles may find them tight. This is the most common complaint in the reviews.
The mix and match options let you purchase single sets or three-pack bundles, which is convenient if you want to stock up for the season. The colors are vibrant and resist fading through repeated washing.
Best Use Cases and Warmth
This set is ideal for indoor wear, light outdoor activity, and sleep. The 100% cotton construction breathes well, making it comfortable for extended wear in heated indoor environments where synthetic fabrics might feel stuffy.
For outdoor cold weather activity, I would rate this as a 35 to 55 degree performer. Cotton absorbs moisture rather than wicking it, so this is not the right choice for sweaty activities or wet conditions.
Sizing and Material Quality
The sizing runs small according to both my experience and the majority of customer reviews. I recommend sizing up at least one size from your usual. The tight ankle and wrist openings are a result of the spandex rib construction.
The 100% cotton material holds its shape well after washing when you follow care instructions. Machine wash cold and tumble dry low for best results. The fabric softens with each wash, which actually improves comfort over time.
Buying Guide: How to Choose Long Underwear for Men?
Choosing the right thermal underwear comes down to understanding four key factors: material, weight, fit, and intended use. Get these right and you will stay warm and comfortable all winter. Get them wrong and you will either freeze or sweat through your base layer.
I have broken down each factor based on what I learned through testing these 8 options across different conditions and activity levels.
Material Types and Their Tradeoffs
Merino wool is the premium choice for serious outdoor enthusiasts. It naturally regulates temperature, resists odor for multiple wears, and wicks moisture effectively. The downsides are cost and care requirements. Merino requires gentle washing and costs significantly more than synthetic or cotton options.
Synthetic fabrics (polyester and spandex blends) dominate the mid-range market. They wick moisture faster than cotton, dry quickly, and offer excellent stretch and mobility. Fleece-lined synthetics provide the most warmth per dollar. The main drawback is odor buildup after multiple wears, since synthetic fibers hold onto bacteria.
Cotton and cotton blends are the budget-friendly classic option. They are soft, breathable, and comfortable for indoor or light use. Cotton absorbs moisture rather than wicking it, which means it stays wet and cold when you sweat. This makes cotton a poor choice for active cold weather use but fine for everyday comfort.
Weight Categories Explained
Lightweight thermals (under 200 g/m²) are designed for mild cold or high-intensity activities. They provide a thin layer of insulation while maximizing breathability. Choose these for active winter sports or temperatures in the 40 to 55 degree range.
Midweight thermals (200 to 280 g/m²) are the most versatile category. They balance warmth and breathability for a wide range of conditions. Most people need only a midweight pair to cover their everyday winter needs from 20 to 45 degrees.
Heavyweight thermals (280+ g/m²) are built for extreme cold and low activity. They prioritize maximum insulation over breathability and mobility. Choose these for outdoor work, hunting, ice fishing, or any situation where you face extended exposure to temperatures below 20 degrees.
Fit and Sizing Guidance
Base layers should fit close to the skin to work effectively. A loose base layer traps less body heat and can bunch uncomfortably under outer layers. Look for a snug but not restrictive fit that moves with your body.
Pay attention to brand-specific sizing variations. Several options on this list run small (Andrew Scott) or large (CL convallaria). Always check recent reviews for sizing feedback before ordering, as brands sometimes change their fit between production runs.
If you fall outside standard sizing, look for brands that explicitly offer big and tall options. The CL convallaria set earned praise from larger customers, while several premium brands assume a slim athletic build.
Moisture Management and Breathability
Moisture-wicking is what separates functional base layers from simple underwear. When you sweat, the base layer should pull moisture away from your skin and spread it across the fabric surface for evaporation. This keeps your skin dry and prevents the cold chill that comes from damp fabric.
Merino wool and quality synthetics excel at moisture management. Cotton absorbs moisture and holds it against your skin, which is why cotton thermals feel cold and clammy during activity. If you plan to be active in your thermals, avoid cotton blends.
Breathability works hand in hand with moisture wicking. A breathable fabric allows water vapor to escape, which prevents the buildup of humidity inside your clothing system. Flatlock seams and gusseted construction also improve airflow in key areas.
Odor Resistance for Multi-Day Wear
Odor resistance matters more than most people realize. If you wear your thermals for outdoor activities or travel, you want a pair that stays fresh across multiple wears. Merino wool naturally resists odor-causing bacteria, making it the best choice for multi-day use.
Synthetic fabrics treat odor with chemical coatings that wear off over time. Some synthetics handle odor better than others, but all eventually develop that persistent sour smell after repeated wears without washing.
Cotton falls in between. It does not resist odor as well as merino, but it does not hold onto bacteria as aggressively as synthetic fabrics. For daily wear with regular washing, odor is rarely a significant issue with any material.
Care Instructions to Extend Life
Proper care extends the life of your thermals significantly. Merino wool requires cold water washing and flat drying to prevent shrinkage and fiber damage. Never use hot water or heat drying on wool products.
Synthetic thermals are more forgiving. Most can handle machine washing on cold and tumble drying on low. Avoid fabric softeners, which coat the fibers and reduce moisture-wicking performance over time.
Cotton thermals are the easiest to care for but watch for shrinkage. Wash in cold water and dry on low heat to maintain size and shape. The Place & Street set in particular is known for top shrinkage after hot washing.
Frequently Asked Questions
What is the difference between thermals and long underwear?
There is no practical difference between thermals and long underwear. Both terms describe the same garment: a thin insulating base layer worn under regular clothing to trap body heat in cold weather. Long johns and base layers are also interchangeable names for the same product. The terminology varies by region and brand, but the function is identical.
What are men’s long underwear called?
Men’s long underwear goes by several names including thermal underwear, long johns, base layers, and thermal tops and bottoms. All refer to the same type of close-fitting insulating garment worn beneath outer clothing in cold conditions. The term base layer is most common in outdoor and athletic contexts, while long johns and thermals are more traditional everyday terms.
Which brand has the best thermals?
For premium merino wool thermals, Smartwool and Merino.tech are the top performers in our testing. For value-oriented synthetic thermals, Cuddl Duds and Thermajohn deliver excellent warmth and comfort at reasonable prices. The best brand depends on your budget, intended use, and material preference. Smartwool wins for outdoor performance while Cuddl Duds offers the best overall value.
What material is best for thermal underwear?
Merino wool is the best material for active cold weather use because it regulates temperature naturally, resists odor, and wicks moisture effectively. Synthetic polyester blends offer the best value and fastest drying times. Cotton blends are the most affordable and comfortable for light indoor use but hold moisture and are not ideal for active outdoor wear.
Final Thoughts on the Best Long Underwear for Men
Finding the best long underwear for men in 2026 comes down to matching the material and weight to your specific cold weather needs. After testing 8 options across different conditions, three recommendations stand out clearly.
For premium outdoor performance, the Smartwool Merino 250 is unmatched in natural temperature regulation and odor resistance. For the best overall value, the Cuddl Duds Heavyweight set delivers a 4.8-star rated warmth at a reasonable price. And for budget-conscious buyers, the Place & Street cotton set offers solid everyday comfort under $20.
The right pair of thermals transforms winter from something you endure into something you enjoy. Pick the option that fits your climate, your activities, and your budget, and you will stay warm and comfortable all season long.