Base Layer & Thermal Underwear

25% Off

$45.00

~~$60.00~~

Meet the all-new UA Base™—delivering the same trusted warmth without the bulk—now softer and smoother than ever for unmatched comfort on every adventure. UA Base™ 2.0 Active Baselayer is lightweig...

40% Off

Person wearing a black long-sleeve top and blue pants with a beige cap on a light gray background

Person wearing a black hoodie and gray pants on a light gray background

$39.00

~~$65.00~~

The super soft UPF 50 hoody for adventures big and small Perfect for giving it your all on the next pitch or pacing on your favorite trail, the Butter™ Long Sleeve Hoody is big on performance witho...

40% Off

Person wearing a black long-sleeve top and maroon puffer pants with a purple beanie on a light gray background

Person wearing a purple long-sleeve shirt and green pants on a light gray background

$36.00

~~$60.00~~

Crucial UPF 50 sun protection that’s moisture wicking and anti-odor for running solo or layering. Make every high effort outing smooth as butter with a long-sleeve layer that’s worth its weight in ...

Woman wearing a black long-sleeve athletic shirt on a white background

Person wearing a black full-body suit on a white background

$90.00

An all-season favorite, the Women's Classic All-Season Merino Base Layer Long Sleeve can be sported as a base layer in the fall or summer when it's time to go backpacking. This base layer features ...

40% Off

Mountain Hardwear Men's Butter Up™ Long Sleeve Shirt

$36.00

~~$60.00~~

Crucial UPF 50 sun protection that’s moisture wicking and anti-odor for running solo or layering. Make every high effort outing smooth as butter with a long-sleeve layer that’s worth its weight in ...

Smartwool Kids' Classic Thermal Merino Base Layer Crew

$65.00

Our Kids' Classic Thermal Merino Base Layer Crew is made of 100% responsibly sourced Merino wool to help your little ones stay comfortable on snow days and activities in the mountains. With a flatl...

33% Off

Three children wearing black wetsuits on a white background

$19.99

~~$30.00~~

This form-fitting, lightweight base layer will help keep you warm and dry. Its wicking properties take moisture away from your body while the poly blend fibers help keep you warm. Active stretch an...

$43.00

~~$0.00~~

Our Men's Active Stretch Bottom offers superior moisture-wicking performance combined with thermal warmth to keep you comfortable during any activity. Its flexible, stretch fabric moves with you, p...

Black long-sleeve shirt on a white background

$43.00

~~$0.00~~

Our Men's Active Stretch Crewneck delivers reliable thermal performance with a comfortable, flexible fit. Designed to wick moisture and retain warmth, this top keeps you dry and cozy during intense...

$43.00

~~$0.00~~

The Women's Active Stretch Crewneck is a versatile long-sleeve base layer designed to keep you comfortable and dry during any activity. Its moisture-wicking fabric moves with you, providing a snug ...

$43.00

~~$0.00~~

The Womens Active Stretch Tight combines moisture-wicking technology with thermal warmth to keep you comfortable and dry. Its stretchy, close-fitting fabric moves with your body, providing support ...

Person wearing black leggings on a white background

Person wearing black long-sleeve top and leggings on a white background

$90.00

Our Women's Classic All-Season Merino Base Layer Bottoms are the perfect layer to put on for your warm-weather adventures. Made of lightweight, breathable Merino, these base layer pants have an upd...

25% Off

Coldpruf Polypropylene Underwear Crewneck Shirt - Kid's

$14.99

~~$20.00~~

Sizes: XS(4-5), S(6-8), M(10-12), L(14-16), XL(18-20).The Enthusiast underwear program by Coldpruf features single-layer 100% polypropylene construction. It is designed to give a close comfortable ...

Black long-sleeve athletic shirt on a white background

$37.99

~~$0.00~~

Performance that moves with you. The ColdPruf® Style 49A Performance Crew is built for cold to very cold weather and medium- to high-activity levels. Its athletic, close-to-body fit makes it an exc...

$37.99

Performance that moves with you. Designed for cold to very cold conditions and medium- to high-activity levels, the ColdPruf® Style 89A Performance Crew is a versatile base layer that can also be w...

5% Off

Black compression pants on a white background

$37.99

~~$40.00~~

Performance that moves with you. Designed for cold to very cold conditions and medium- to high-activity levels, the ColdPruf® Style 89B Performance Pants deliver essential warmth, comfort, and flex...

$37.99

~~$0.00~~

Performance that moves with you. The ColdPruf® Style 49B Performance Pants are designed for cold to very cold weather and medium- to high-activity levels. With a close athletic fit, they sit just b...

$48.00

~~$0.00~~

Billowy warmth without added weight, Micro Fleece under layers are durable and breathable. When it's really chilly outside, let our Micro Fleece keep you warm so you can focus on fun! Our Micro Fle...

$48.00

~~$48.00~~

Extremely soft warmth without weight, our Micro Fleece base layer shirt is durable and breathable. When it's really cold outside, this microfiber polyester crew is an excellent choice for layering ...

$49.00

~~$0.00~~

Originals thermal tights are a long time kids' favorite with a soft cotton-like hand feel that does not hold moisture. Made with MTF Moisture Transfer Fibers, these children's winter tights move...

Black long-sleeve shirt with blue accents on a white background

$49.00

~~$0.00~~

If you're looking for classic children's thermal, look no further than Hot Chillys Originals. Improving on the qualities that made the first generation so popular, this updated thermal underwear ...

Person wearing a black long-sleeve top and leggings on a white background

$115.00

100% Merino. 100% capable. Our Women's Merino Base Layer Bottom is always ready for what's ahead and what's next. With a fit updated to improve functionality while enhancing aesthetics for a ran...

Coldpruf Journey Single Layer Fleece Pant - Women's

$19.99

~~$0.00~~

Regular fit pants Comfort waistband Front and back rise Single layer, lightweight fleece Rib cuffs Technology: 100% ColdPruf® Technical Fiber Polyester with SILVADUR™ Intelligent Freshness ...

24% Off

$25.99

~~$34.00~~

jersey knit that locks in warmth by trapping air between the layers. These midweight base layer pants utilize Acclimate Dry hydrophobic yarns to effectively wick moisture away, keeping you dry and ...

24% Off

$25.99

~~$34.00~~

Made with a special two-layer soft jersey knit, this Polarmax Double Layer thermal is sure to keep you warm when you need it most. The unique double layer construction of this women's crew neck bas...

24% Off

$25.99

~~$34.00~~

Experience ultimate warmth with our men's thermal top, featuring a two-layer soft jersey knit and a unique double layer construction for superior thermal retention. The special Acclimate Dry hydrop...

24% Off

Navy blue leggings on a white background

$25.99

~~$34.00~~

Experience exceptional warmth and comfort with our Men's Double Layer Bottoms. Featuring a unique two-layer soft jersey knit construction, these bottoms offer superior thermal insulation by trappin...

23% Off

Terramar ThermaSilk CS Silk Lightweight Long Sleeve Tall Crew Shirt - Men's

$49.99

~~$65.00~~

The Miracle of SilkAfter 4000 years, nature and science have joined forces to produce silk long underwear which can help thermo-regulate the body's temperature and dramatically speed up the dispers...

Smartwool Women's Intraknit Thermal Merino Base Layer Crew

$130.00

This minimalist-style crew is anything but insignificant. Our Women's Intraknit™ Thermal Merino Base Layer Crew is a lightweight, super-moveable top, made for all of your most extreme cold-weather ...

Base Layer

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