LIGHTWEIGHT WARMTH
Warmth without unnecessary bulk.
WARM LIKE DOWN, WORKS LIKE WOOL
SEEN ON SHARK TANK / PATENTED USA INSULATION
Discover lightweight, cold-weather gear powered by Our Patented AERIS™ insulation for work and outdoor adventures
Shop by Category
Explore cold-weather gear built for work, adventure, and everyday performance.
FORTRESS CLOTHING · USA-MADE INSULATION
MEET AERIS™ INSULATION
USA-made insulation. Engineered for real-world cold.
Lightweight warmth, designed to help simplify cold-weather layering—from demanding days outdoors to everyday winter wear.
DESIGNED FOR WET CONDITIONS
Explore tested AERIS performance in wet conditions.
FEWER LAYERS. MORE FREEDOM.
A simpler approach to cold-weather layering.
Shop By Temp˚
From cool mornings to extreme winter conditions, find the right Fortress gear for your environment.
Mild cold
20°F to 60ºF
Lightweight warmth for cool mornings, everyday wear, and changing conditions.
Cold weather
-5°F to 50°F
Versatile insulation and strategic layers for cold days at work or outdoors.
Shop Extreme cold
Below -30°F to 40ºF
Insulating layers and cold-weather gear for demanding winter conditions.
Temperature ranges are general shopping guides, not guarantees of comfort at a particular temperature.
Field tested. Customer trusted.
BUILT FOR THE COLD. TRUSTED BY CUSTOMERS.
“ I slept overnight in just the base layers in temperatures ranging from 20°F to 50°F. My military bag only contained food, water, and basic survival gear, so I had no other clothing or bedding to rely on.” Lincoln O.
GEAR BASED ON ACTIVITY
WORK
Insulated clothing for demanding workdays and cold conditions.
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HUNT & FISH
Cold-weather layers and accessories for outdoor pursuits.
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EVERYDAY WINTER
Versatile warmth for commuting, travel, and daily wear.
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WOMEN'S GEAR
Explore cold-weather clothing and accessories designed for women.
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WATCH THE PROOF
Explore the design, materials, and performance behind every layer.
BUILT FOR THE CONDITIONS
BUILD YOUR COLD-WEATHER SYSTEM
Start with the right base layer. Add the protection your conditions demand.
Step 01
START WITH BASEPRO
Build your foundation with Fortress BasePro, designed to work as the first layer in a cold-weather system.
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Step 02
Jackets Vests
Choose a jacket, hoodie, or insulated layer to match your activity and exposure.
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Step 03
FINISH WITH THE ACCESSORIES
Complete your setup with pants, gloves, mittens, socks, and the accessories your day calls for.
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