Extended “Extreme” Cold Weather Clothing System

-- How to Wear ECWCS Gen III

Extended “Extreme” Cold Weather Clothing System

The history of the Extended Cold Weather Clothing System (ECWCS) started in the 1980’s with garments originally developed by the United States Military for soldiers faced with cold environments for extended periods of time. Officially dubbed “Extended Cold Weather Clothing System” many refer to it as Extreme Cold Weather Clothing System or ECWCS. The ECWCS system consists of multiple layer options that can be worn in combination to provide adequate protection for individuals in temperatures from +40 to -60! Over the years the ECWCS system has gone through multiple improvements with technology advancement and material evolution. The most advanced and most popular is ECWCS Generation III.

Three Generations of ECWCS


Generation I was intended to be used as a tri-layer system consisting of:

  • A synthetic base layer
  • An insulated and water or wind-resistant mid-layer made of synthetic or cotton blends
  • The outer layer was often made from Gore-Tex and designed for protection from wind, rain and snow

In total, this system consisted of 23 individual garments including; gloves, mittens, base layers, trousers, parkas, socks and liners.


Generation II remained largely unchanged from Generation I with the exception of Polartec Fleece, renowned for its outstanding insulative properties, even when wet, and its lightweight construction.


Generation III was a drastic evolution from the previous design with additional mid-layers made of Polartec fabrics including Power Dry and Thermal Pro High Loft in addition to our favorite, Primaloft. Gen III ECWCS gear consists of seven independent layers each of which can be worn as part of a system or on their own. The seven levels are:

Effective use of ECWCS III Layers

The Base Layer: Crucial to the function of ECWCS is a high quality synthetic base layer designed to quickly wick moisture away from the skin to prevent chafing and allow the other layers to work more effectively. The ECWCS system includes a lightweight and midweight option for varying temperatures, metabolism or planned physical exertion, both Levels I (1) and Level II (2) are base layers.

The Mid-Layer: Mid layers are designed to provide the bulk insulation by trapping a layer of warm air against the body. Although the concept has remained the same for years high tech materials including; aramid, Primaloft and Polartec Fleece are now found in mid-layers. These exotic materials offer light weight, better insulation even when wet and are flame resistant or flame-proof. Levels III (3) and Level IV (4) are considered mid layers, though these can be worn on their own in moderate conditions with little wind or precipitation.

ECWCS Level III fleece, Coyote


ECWCS Level III fleece, Foliage Green

ECWCS Level III fleece, Foliage Green

ECWCS Level III fleece, Coyote

Special Forces Polar Fleece, Black

The Outer Layer: The last three levels including Level V (5), Level VI (6) and Level VII (7) are considered outer layers designed to provide insulation and additional protection from wind, rain and snow.

  • Level V (5) is a combination of soft-shell jacket and trousers. It offers excellent freedom of movement, good protection from snow and sleet with moderate protection from heavy, wet snow or rain.
  • Level VI (6) offers the best protection from wind, rain and wet snow. It features dual layers of Gore-Tex with taped and welded seams that virtually eliminates any intrusion of moisture with outstanding breathability.
  • Level VII (7) is considered the holy grail for many backcountry enthusiasts especially those who operate snowcats, snowmobiles or spend extended time in dry, cold to extremely cold environments without high levels of activity. Though generally considered water resistant Level VII is best used when temperatures are well below freezing when exposure to water is not likely.

ECWCS Level VII, Parka

ECWCS Level VII, Parka

ECWCS Level VI, Jacket

ECWCS Level VI, Jacket

ECWCS, Level VII Trousers

ECWCS, Level VII Trousers

The modular ECWCS system allows users to custom tailor their Extended Cold Weather Clothing System to meet the demands of their unique environment, expected physical exertion and personal metabolism. With decades of development and improvement of materials once too exotic for clothing, our soldiers and civilians have access to clothing designed to withstand the harshest environments without the burden or bulk of previous cold weather materials.

  • J
    Posted at 00:30h, 25 September Reply

    I do love the gortex wet jacket and pants. Versatile and has a roll hood. Pity it costs a lot.

  • Fred Ernst
    Posted at 18:38h, 08 January Reply

    Google ECWCS CIE for the temperature table.

    • Ty
      Posted at 15:46h, 09 January Reply

      Hi Fred,

      Great tip – we’ve heard rumors of an updated Technical Manual. As you mentioned it is NOW available via a simple google search.

      Stay Safe,


  • Annoyed
    Posted at 07:48h, 26 May Reply

    Why is it so difficult to find a temperature range for each level.

    • Ty
      Posted at 08:28h, 30 May Reply

      We had the same frustrations! From what we can tell its hard to pin down a temperature range because those ratings are dependent on so many factors including, humidity, wind, physical exertion, etc. The ECWCS sleeping bags do have a tag included that details their temperature ratings, unfortunately they’re the only place we’ve seen that detail.

      Stay warm!

  • Harish Gupta
    Posted at 04:34h, 03 March Reply

    Is there a generation 4 system as well

    • Ty
      Posted at 09:59h, 05 March Reply

      Hi Harish,

      Its hard to say exactly what is in testing and development with the U.S. Military. However we haven’t heard of any Generation 4 systems available in the surplus market.

      Stay Safe (and warm!)

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