Best S Mens Base Layers in 2026

Super-light HeatGear fabric delivers superior coverage without weighing you down

Strategic mesh panels for added ventilation where you need it

Material wicks sweat & dries really fast

Heat Retention: When it comes to warmth and everyday wear, these long johns for men is designed specifically for you to stay protected from the cold.

Ultra Soft Fleece: Designed with a fleece lining & quality material, these ultra soft mens thermal underwear set will keep you feeling comfortable throughout the day.

Moisture Wicking: Stay dry with these long underwear mens as they're made from breathable fabric that effectively wicks away moisture and perspiration.

*Alert: True to size : Please follow the size examples below*(EX: Size "Large recommended";" - Size for 6" 215 lbs.) (EX:size "medium," height "5'9", weight " 165 lbs.)

Washing Tips: Wash separately, by hand, in cold water. Lay flat to dry and do not dry clean.

For all sports and cold-weather activities, the TSLA Thermal Baselayer Series is designed with the best heat insulation and thermal materials.

Odor-resistant

Temperature regulating

Will help keep you cool when your intensity amps up, and its design helps minimize chafing

QUALITY MIDWEIGHT BASELAYER: 100% Merino Wool is super soft and extremely comfortable. This three season merino wool thermal bottom has the versatility and warmth to make this an essential part of your outdoor gear. Fits sizes XS to 6XL and Tall Sizes M-Tall to 4X-Tall (4XL to 6XL and Tall sizes in Black Only) Minus33 offers the largest size selection. Outfitting anyone from the Hard-at-Work to the Hard-at-Play.

WEAR THESE FOR ANYTHING: Hiking, running, camping, overlanding, hunting, ice fishing, skiing, snowboarding, snowshoeing, the activities are endless. Wear this base layer under your clothes for cold weather or just wear them by themselves to lounge around. These thermal long johns are perfect for three season wear. Fall, winter, and spring. Designed to keep you warm, dry, and ready for hours of outdoor fun!

EXPERIENCED BRAND: Although there are many copy-cats on the market today, Minus33 has been a trusted brand since 2004. We see it all – from beautiful fall leaves, to white, snowy winters, to colorful springs and summers. We’re New Englanders, plain and simple. We’ve been hiking, camping, skiing, and everything else in between since we were kids. No amount of snow keeps us down, and we only continue to thrive in the summer.

LIGHTWEIGHT – Mens Merino Base Layer Available in: Lightweight = 165 g/m², Midweight = 250 g/m², Heavyweight = 320 g/m². FREE MERINO WOOL HIKING SOCKS ($21 VALUE!) –  Lightweight Merino Wool Pants for Men 165 g/m² + Wool Socks. Cool Packaging! MAKES A GREAT GIFT!

SUPER SOFT & COMFORTABLE – 100% Superfine 18.5 Micron Merino Wool Underwear Mens provide all day comfort and no itch! Designed for daily wear without rubbing and overheating of regular cotton.

MOISTURE WICKING & ODOR RESISTANT – Merino Baselayer Men natural wicking and odor-resistant properties allow it to absorb moisture better than any other fabric, keeping you dry and fresh.

Waffle knit traps heat, fast dry wicks away sweat and fights odor

Rugged flex technology for ease of movement

Smooth flatlock seams and tagless label enhance comfort

ULTIMATE THERMAL RETENTION: Designed with high quality fleece lining, the thermal underwear mens is windproof, Set of long sleeve thermal shirt and bottoms can keep you warm while running, cycling, hiking, hunting, jogging or walk the dog for extreme cold weather.

WICKING BREATHABILITY & QUICK DRY: Breathable and moisture wicking fabric is perfect to keep sweat away and dry fast, it perfectly repels odors and unpleasant smells left behind from sweat and dirt, enjoy your outdoor tactical training or sports freely.

STRETCHABLE & ABRASION RESISTANT: Made of 91% polyester+ 9% spandex, this thermal underwear offers maximum freedom and support of your body, protecting your muscle trauma during training and keeping you stay comfortable. Flatlock stitching creates a flat seam to the garment to ensure maximum comfort and prevents chafing.

MERINO BENEFITS: The breathable interlock knit merino wool is perfect for maintaining thermal comfort to keep you cool when it's hot, and warm when it's cold so you can stay comfortable in any season. 🐑Our 100% natural Australian merino wool is ethically sourced from non-mulesed sheep.

STAYS FRESH: Whatever the season, this thermal will be a solid choice in your wardrobe as the Merino wool has naturally hygienic properties to keep you fresh through the day regardless of the weather.

IT GOES WHERE YOU GO: The durable 4-way stretch rib knit hem and snug fit will flex, conform, and move with your body to maintain range of motion and comfort. Whether you're camping, hiking, snowboarding, working out, working, or just taking it easy, this comfy thermal has got you covered.

🔥Must-have Winter Thermals: Our men's warm and comfortable base layer is the best all-around thermal underwear for men. Made of 92% polyester and 8% spandex, the spandex makes them extra flexible so the baselayer feels snug and cushy, and the polyester provides a strong kick of insulation to keep you toasty. This long underwear mens is also soft—a Fleece Lined gives a velvety feel against your skin, provides definitive comfort while keeping your whole body warm.

🎁Fits like a Glove: Fit is the key to warmth, our long johns for men are designed to fit skin tigh to keep you warm yet dry and cozy and do a great job blocking wind. The Top & Bottom Set are reinforced with design details on the elastic collar at the neckline, cuffs and other joints to help you withstand the cold. The pants will not only help keep warm, they will also reduce soreness in your legs after an intense day in the backcountry. Nice gift for your husband, father, boyfriend, son!

🔥Lightweight & Durability: These thermals for men are tailored specifically to a man’s body and provide a form-fitting but unconstricting fit. The 4-way stretch delivers full mobility and a squat proof design, its strong seams won’t tear prematurely. For even more added comfort, mens thermal underwear set have no tags, which reduces any skin irritation. And the thermal pant has a stretchy elastic waistband that helps to fit most body types. You can slip them on and off easily.

The original technical Helly Hansen long sleeve base layer.

Lifa: lifa is the original Helly Hansen base layer made of 100% lifa Fibers, providing warmth and insulation in cold weather. Lifa naturally pulls moisture away from skin and to the outer layer of The garment keeping you warm, dry and comfortable.

Features: lightweight insulation, 100% lifa, flatlock seams for max comfort, natural stretch fabric

PRODUCT FEATURES: Fitted, 28.5" Body Length (Size M), Moisture Wicking, Anti-Odor, 4-Way Stretch, Tag-Free Label, Imported

FABRIC: 40% Polyester - 34% Acrylic - 22% Rayon - 4% Spandex - Lightweight knit with a lot of stretch. The acrylic blend adds additional lightweight warmth that is comfortable against the body.

CARE INSTRUCTIONS: Wash Cold Gentle Cycle With Like Colors, Non-Chlorine Bleach Only, Tumble Dry Low, Iron Cool (if needed), Do Not Dry Clean

Second Skin Wool Leggings: Harness natural performance with the Icebreaker Merino Everyday 175 Long Warm Leggings and Men’s Undergarments! These insulated long johns for men are the perfect foundation for an everyday cold weather men base layer.

Reliable Performance: The ideal warm leggings for men, this 100% Merino wool base layer for mens use is ready for any active day! Our men’s long underwear is naturally odor-resistant, and will keep you warm when it’s cold and cool when it’s warm.

Always the Perfect Fit: Perfect for summer nights at camp or a winter adventure, these warm men’s leggings have a contoured, slim fit for smooth layering. Our men’s thermals and winter pants for men are super soft and will help to manage moisture!

Package Includes: 1 - Men’s 250g/m² merino wool thermal leggings

SUPER SOFT: 100% all natural superfine 18.5-micron Merino wool ensures comfort all day long – no itch! EASY CARE: Your thermal pants are machine-washable on cold setting and safe to tumble dry on low heat with like colors, so it’s ready when you are for your next adventure. MEN’S SIZE OPTIONS: XS to 3XL.

BREATHABLE: Keeping you cool in summer and warm in winter, MERIWOOL’s 250g/m2 weight interlock-knit Merino wool can be used as a base layer or mid-layer, but won’t weigh you down. COMFORTABLE & CONVENIENT: Quick-drying pants feature a loop for hang drying while camping, hiking, hunting, working, playing sports, skiing, or partaking in any outdoors activity.

Men's long-sleeve pullover undershirt and bottoms. Dickies base layer winter gear add an extra layer of warmth to your cold-weather looks with these long-sleeve base layer long johns for men from Dickies.

The cotton/spandex-blend fabric of this mens base layer set keeps you comfortable and warm. This men's long-sleeve base layer wear undershirt is made from a soft, moisture-wicking fabric blend.

Dickies mens long johns poly-spandex construction grants enhanced insulation, and the cozy flat lock pattern helps trap warmth and keep you comfortable all through the winter days without any extra bulk.

PRODUCT FEATURES: Fitted, 27 ½" Inseam (Size M), Moisture Wicking, Anti-Odor, 4-Way Stretch, Functional Fly, Elastic Waistband, Tag-Free Label, Imported

FABRIC: 40% Polyester - 34% Acrylic - 22% Rayon - 4% Spandex - Lightweight knit with a lot of stretch. The acrylic blend adds additional lightweight warmth that is comfortable against the body.

CARE INSTRUCTIONS: Wash Cold Gentle Cycle With Like Colors, Non-Chlorine Bleach Only, Tumble Dry Low, Iron Cool (if needed), Do Not Dry Clean

100% Merino Wool - The material of the Merino wool shirt is imported from Australia and New Zealand, where Merino sheep are bred. Most sheep are shorn once per year, then like with human air the MERINO Wool grows back naturally with perhaps the help of grass, and water.

Odor Resistance - Merino wool has a special fiber structure that helps you get rid of the funky smell when you sweat

Temperature Regulation - One of the best-known features of Merino wool is that it helps you stay cool in hot summers and stay warm in snowy winters.

【PERFORMANCE COMPRESSION SHIRTS】GYM SHIRTS designed for men. Tight fit for a body-hugging feel.

【BREATHABLE ATHLETIC SHIRT】Mens base layer MOISTURE WICKING performance allows the compression shirt to dry quickly. Comfortable to be worn all day.

【CLASSIC& STYLISH DESIGN】Ergonomic seam design follows the natural lines of the body.

Made of 86% Polyester and 14% Spandex, this New Balance Men's Base Layer Pant will keep you warm and comfortable during all of your activities. Available in mutliple colors and in sizes Small, Medium, Large, X-Large and XX-Large.

Super soft and plush, the elastic waistband is non-rolling so there is no need to worry about the waistband folding or collapsing. The spandex material allows for freedom of movement while being comfortable.

Base layer pants feature a 3M reflective pill tape. The logo on the side of the pant and back of calves are also reflective to ensure you are safe and seen during evening activities.

Wicking finish

Midweight for comfortable warmth

Flexible waistband

OFFICIAL REEBOK: Performance Base Layer Thermal Long Sleeve Shirt for Men; Greatness doesn’t come from standing still, Living an active life enables people to be their best selves

MOISTURE CONTROL: Men’s athletic performance base layer shirt wicks moisture to keep you dry during intense workouts, practices, and games

PERFORMANCE STRETCH: Compression long sleeve shirts for men have a stay put design so they won't ride up; Stretch fabric offers a full range of motion for peak performance

Rugged Flex moves with you; FastDry wicks away sweat; fights odor

Strategically placed flatlock seams reduce chafing

Brushed elastic waistband with concealed stitching

Mens 2-Piece Waffle Thermal Set Includes 1 Crew Neck Long Sleeve Top and 1 Pant. Active Stretch Fabric Provides Easy, Flexible Movement All Day. Heat Retention Circulates Body Heat To Keep You Warm.

ACTIVE STRETCH: Moves and Stretches with the Body, Flexible & Comfort Fit. Keeps You Warm and Provides Flexible Movement.

BREATHABLE: Innovative Finish that Allows Fabric to Breathe. Great Performance In Warm Or Cool Weather.