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Polarmax Double Layer
Built for Cold.
Built for Work.

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Performance Thermal Base Layers For Real-World Cold

Built on 40 Years of Cold-Weather Experience

From job sites to backyards to backcountry trails, Polarmax has been helping people stay warm and comfortable for generations.

Customer care

Built for cold. Backed by people who care. Our US-based customer support team is here to make sure you’re taken care of — before and after every order.
Black long-sleeve shirt with a quarter zip on a white background

Mountain Fleece Thermals

Mountain Fleece is the warmest Polarmax base layer, designed for very cold conditions and low-to-moderate activity where maximum warmth and comfort matter most.

  • Heavyweight thermal fleece for very cold weather
  • Synthetic, non-wool fabric for itch-free warmth
  • Relaxed fit
  • Mechanical stretch for natural movement without elastic fibers
  • Structured feel that maintains shape during extended wear
  • Soft fleece interior for next-to-skin comfort
  • Designed to layer smoothly under outerwear
  • Best for: Very cold conditions, skiing, snowmobiling, standing or low-output activity
  • Not ideal for: High-output activities
Polarmax black long sleeve top made with thermal microfleece fabric for warmth and comfort

Microfleece Base Layers

Microfleece is a midweight thermal layer designed for moderate to high activity in cold conditions. It delivers soft, breathable warmth while maintaining flexible movement, making it ideal for layering or as a standalone base layer on active days.

  • Midweight synthetic fleece for soft, breathable warmth
  • Flexible, movement-friendly stretch for unrestricted activity
  • Suitable as standalone or layering base layer
  • Moisture-wicking for quick drying during activity
  • Non-wool construction for itch-free comfort
  • Maintains shape and performance through extended wear and wash cycles
  • Perfect for active outdoor cold-weather use
  • Best for: Moderate to high-output cold-weather activities. Users seeking balanced warmth without bulk.
  • Not ideal for: Very cold, stationary conditions requiring maximum insulation. Low-output use where bulkier warmth is preferred.
Black long-sleeve shirt on a white background

Active Stretch Base Layers

Active Stretch is a performance stretch body fit construction that allows the fabric to move freely with the body during dynamic activity, supporting mobility without restricting movement or losing shape.

  • Designed for active movement and dynamic use
  • Stretches with the body to reduce restriction
  • Maintains fit during bending, squatting, and extended wear
  • More flexible than mechanical stretch fabrics
  • Comfortable for performance layering
  • Best for: Cold-weather activities with frequent movement, moderate to high output use.
  • Not ideal for: Very cold conditions with minimal activity
Polarmax Women's Double Layer Crewneck Cross Country Blue

Double Layer Thermals

Double Layer Thermals combine a dual-layer fabric construction to provide extra warmth without excessive bulk. Engineered for moderate activity in cold conditions, they move with the body while maintaining fit and comfort.

  • Dual-layer fabric construction for balanced warmth and comfort
  • Provides extra insulation without bulk
  • Comfortable for all-day wear and layering
  • Synthetic, non-wool construction for itch-free performance
  • Durable through repeated use and wash cycles
  • Works as a midweight base layer between lightweight and heavyweight options.
  • Best for: Sustained cold and moderate activity. All-day warmth with consistent comfort.
  • Not ideal for: Mild conditions where overheating may occur. High-output, dynamic activity.
Black thermal baselayer leggings with a brand logo for men

Men's Active Stretch Bottom

Men's Active Stretch Bottom
$ 50.00
    • Black long-sleeve shirt on a white background

    Men's Active Stretch Crewneck

    Men's Active Stretch Crewneck
    $ 50.00
    • Polarmax Men's Base Layer Pants for Men in Black, Ideal for Comfortable Layering in Cold Weather

    Men's Double Layer Bottoms

    Men's Double Layer Bottoms
    $ 40.00
    • Polarmax men's thermal base layer shirt in black long sleeve top for cold weather

    Men's Double Layer Crewneck

    Men's Double Layer Crewneck
    $ 40.00
    • Black and red socks with visible branding on a white background
    Sold out

    Men's Low Volume Winter Sport Sock

    Men's Low Volume Winter Sport Sock
    $ 30.00
    • Polarmax black men's merino wool base layer long sleeve top for thermal comfort and moisture control

    Men's Merino Wool Crewneck

    Men's Merino Wool Crewneck
    $ 60.00
    • Polarmax black men's merino wool base layer long bottoms for cold weather

    Men's Merino Wool Tight

    Men's Merino Wool Tight
    $ 60.00
    • Men's MicroFleece Boot Tech Tight
    Sold out

    Men's MicroFleece Boot Tech Tight

    Men's MicroFleece Boot Tech Tight
    $ 57.50

    • Customers are saying

    3.97 ★ (36)
    Verified
    Collection Fabric Content GSM Warmth Weight Stretch Best For Not Ideal For Origin Link
    Double Layer 100% Polyester 150 Medium Midweight Dual-layer / Mechanical Stretch Sustained cold, moderate activity, layering under looser fitting outerwear High-output activity, mild conditions, use under snug fitting bottoms Imported View →
    Military Fleece 100% Polyester 160 Maximum Midweight-Heavy Mechanical Stretch Extreme cold-weather base layers during low-to-medium activity High-output activities in cool weather Imported View →
    Merino Wool 67% Polyester / 28% Merino / 5% Spandex 175 Medium Midweight Four-way / Flexible Cold conditions, moisture management, odor control, multi-day wear Heavy-duty work use or warm weather Imported View →
    Single Layer 100% Polyester 175 Light Lightweight Mechanical Stretch High-output or dynamic activity requiring maximum breathability Very cold or stationary conditions Imported View →
    Active Stretch 84% Polyester / 16% Spandex 180 Medium Midweight Four-way / High-mobility High-movement cold-weather activity, skiing, snowboarding, outdoor work Low-output stationary use or extreme cold where warmth is top priority Imported View →
    Mountain Fleece 100% Polyester 205 Maximum Heavyweight Mechanical Stretch Very cold conditions, low-to-moderate activity, all-day warmth High-output or dynamic activity Imported View →
    Microfleece 92% Polyester / 8% Spandex 230 Medium-Heavy Midweight-Heavy Four-way / Flexible Heavy-duty work use or cold weather High-output activity Imported View →
    Wool Double Layer 70% Polyester, 30% Wool Outer; 100% Polyester Inner 230 Medium-Heavy Midweight-Heavy Dual-layer / Mechanical Stretch Very cold conditions, low-to-moderate activity, all-day warmth High-output, warm weather or dynamic activity Imported View →

    Double Layer

    Fabric Content 100% Polyester
    GSM 150
    Warmth Medium
    Weight Midweight
    Stretch Dual-layer / Mechanical Stretch
    Best For Sustained cold, moderate activity, layering under looser fitting outerwear
    Not Ideal For High-output activity, mild conditions, use under snug fitting bottoms
    Origin Imported
    View →

    Military Fleece

    Fabric Content 100% Polyester
    GSM 160
    Warmth Maximum
    Weight Midweight-Heavy
    Stretch Mechanical Stretch
    Best For Extreme cold-weather base layers during low-to-medium activity
    Not Ideal For High-output activities in cool weather
    Origin Imported
    View →

    Merino Wool

    Fabric Content 67% Polyester / 28% Merino / 5% Spandex
    GSM 175
    Warmth Medium
    Weight Midweight
    Stretch Four-way / Flexible
    Best For Cold conditions, moisture management, odor control, multi-day wear
    Not Ideal For Heavy-duty work use or warm weather
    Origin Imported
    View →

    Single Layer

    Fabric Content 100% Polyester
    GSM 175
    Warmth Light
    Weight Lightweight
    Stretch Mechanical Stretch
    Best For High-output or dynamic activity requiring maximum breathability
    Not Ideal For Very cold or stationary conditions
    Origin Imported
    View →

    Active Stretch

    Fabric Content 84% Polyester / 16% Spandex
    GSM 180
    Warmth Medium
    Weight Midweight
    Stretch Four-way / High-mobility
    Best For High-movement cold-weather activity, skiing, snowboarding, outdoor work
    Not Ideal For Low-output stationary use or extreme cold where warmth is top priority
    Origin Imported
    View →

    Mountain Fleece

    Fabric Content 100% Polyester
    GSM 205
    Warmth Maximum
    Weight Heavyweight
    Stretch Mechanical Stretch
    Best For Very cold conditions, low-to-moderate activity, all-day warmth
    Not Ideal For High-output or dynamic activity
    Origin Imported
    View →

    Microfleece

    Fabric Content 92% Polyester / 8% Spandex
    GSM 230
    Warmth Medium-Heavy
    Weight Midweight-Heavy
    Stretch Four-way / Flexible
    Best For Heavy-duty work use or cold weather
    Not Ideal For High-output activity
    Origin Imported
    View →

    Wool Double Layer

    Fabric Content 70% Polyester, 30% Wool Outer; 100% Polyester Inner
    GSM 230
    Warmth Medium-Heavy
    Weight Midweight-Heavy
    Stretch Dual-layer / Mechanical Stretch
    Best For Very cold conditions, low-to-moderate activity, all-day warmth
    Not Ideal For High-output, warm weather or dynamic activity
    Origin Imported
    View →
    Person sitting in snowy forest comparing microfleece vs fleece for warmth during colder weather

    Microfleece vs Fleece for Warmth: Which is Best for You?

      When it comes to staying warm and cozy, fleece and microfleece are two popular choices. But what sets them apart? Let's dive into the key differences between these two...
    Person fishing on a frozen lake wearing a thermal base layer for cold weather activities

    How to Choose the Best Thermal Base Layer for Cold Weather Activities

    As the winter chill sets in, one of the most crucial decisions you'll make is selecting the right thermal base layer to keep you warm and comfortable during your outdoor...
    Person sitting in snowy forest comparing microfleece vs fleece for warmth during colder weather

    Microfleece vs Fleece for Warmth: Which is Best for You?

      When it comes to staying warm and cozy, fleece and microfleece are two popular choices. But what sets them apart? Let's dive into the key differences between these two...