Two-layer construction
A soft inner layer next to the skin paired with a tougher outer layer means better heat retention than single-layer thermals, plus more durability over repeated wear.
A fit that layers well
Close to the body without feeling restrictive, so thermals slide easily under work clothes, hunting gear, or winter jackets without adding bulk.
Options for different needs
Wool for natural warmth and odor resistance, cotton blends for everyday comfort, synthetic fabrics for moisture-wicking performance. Whatever the activity or climate, there’s a fabric built for it.
Choose Your Thermals
Pick your fit, weight, and style, from classic union suits to modern two-piece sets, and find the layer that matches how cold it actually gets where you’re headed.
Mid Weight Wicking Thermal Legging Underwear
Midweight thermal leggings that pull moisture away from skin and hold warmth without bulk, made for active days in cold weather.
Mens Mid-Weight Wicking Crew Neck Top
A midweight crew neck top that wicks moisture and holds in warmth, built for men who stay active when temperatures drop.
Women’s Heavy-Weight Thermal Leggings
Heavyweight double-layer thermal leggings that trap warmth for serious cold while keeping the fit close and comfortable.
Men’s Flex Weight Thermal Shirt
A lightweight thermal shirt with a flexible fit that moves with you, keeping cold at bay without weighing you down.
Men’s Flex Weight Thermal Pant
A lightweight thermal pant with a flexible fit that moves with you, holding in warmth without slowing you down.
Women’s Thermal Wicking Crew
A women’s thermal crew that wicks moisture and keeps you warm through cold, active days.
Women’s Midweight Ankle Length Bottom
Midweight ankle-length thermal bottoms that keep legs warm under pants or leggings without adding bulk.
Flex Weight Thermal Pant Underwear
A lightweight thermal underwear pant with a flexible fit that keeps cold out without restricting movement.
Men’s Lightweight Thermatrix Thermal Shirt
A lightweight Thermatrix performance shirt that regulates temperature and moves sweat away during high-output days.
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About brand
Duofold has been making cold-weather base layers since 1918, back when wool union suits were the only thing standing between a person and a brutal winter. Started in Mount Airy, North Carolina, the brand built its name on double-layer fabric technology: a soft inner layer against the skin paired with a tougher outer layer for insulation, a construction method that’s still at the core of what they make today.
Over the decades, Duofold thermals have shown up on hunters, hikers, construction crews, and anyone else who spends real time outside when the temperature drops. The lineup has grown from classic wool union suits to modern blends using merino wool, cotton, and moisture-wicking synthetics, but the goal hasn’t changed: keep the wearer warm and dry without weighing them down in bulky layers.
Made for people who work outside, hunt at dawn, or just refuse to let cold weather keep them off the trail, Duofold sticks to a simple idea: good base layers should do their job and get out of the way.
FAQ
Duofold uses a two-layer construction: a soft layer against the skin and a tougher layer on the outside for warmth. That combination traps heat better than a single layer of fabric and holds up to repeated wear and washing.
Depends on the line. Some styles use 100% merino wool, others blend cotton with synthetic fibers for moisture control, and some use pure synthetic fabric for lighter, quicker-drying wear. Check the product page for the exact fabric on each item.
Thermals fit close to the body, so most people order their normal size rather than sizing up. If you’re between sizes or plan to layer over the top with heavier clothing, going one size up is usually the safer call.
Yes. Plenty of people wear the union suits and tops on their own around the house or for casual outdoor wear, not just tucked under a coat.
Wool can shrink if washed in hot water or put in the dryer. Stick to cold water and air drying for wool pieces to keep the fit consistent wash after wash.
The heavyweight styles are built for serious cold, hunting stands, outdoor work, sub-zero mornings. For milder weather, a lightweight or midweight option will keep you comfortable without overheating.
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Clients Thought
Real feedback from people who’ve worn these through actual winters, no filler, just what worked and what didn’t.
I bought the merino wool union suit for early morning deer stands and it’s the first base layer that’s actually kept me warm without making me sweat through everything by mid-morning. Wore it through a whole Minnesota winter and it still looks and fits like new.
Karen W.
Customer
I work outdoor shifts at a garden center all winter, so warmth without bulk matters to me. The two-piece thermal set kept me comfortable through single-digit mornings and still fit right under my uniform without feeling tight.
Rachel D.
Customer
I split firewood most weekends through the winter, and the heavyweight thermal top and bottom have held up better than anything else I’ve tried. Warm enough for the cold mornings, breathable enough that I’m not soaked by the time I’ve stacked half a cord.
Marcus B.
Customer