Hiking Info, News, Pictures, Forum, Shop, Travel and Community
Information Articles
 Print Article           Comment on Article           Write New Article         

Extreme Outdoor Hiking Clothing - Base, Insulation, Outer Layer

Outdoor and Hiking Clothing used to be any combination of day to day items of clothing which were used to keep you warm and dry. Nowadays, the generally-accepted way of getting yourself dressed for Hiking and Outdoor Activities is to use a Three-Layer System. Much of the extreme outdoor clothing you can find in outdoor shops is part of this system. In this section, know what the Three Layer System is and what the layers are:

Base Layer / Thermal Underwear

Base Layer & Thermal Underwear The Base Layer is the first layer of clothing you put on and it is in direct contact with your skin. For Outdoor Activities, it is very likely that you will be sweating, cooling down, sweating, cooling down, etc. It is important that your clothing works in a way that it can cool down quickly but not too much. This is where the base layer comes in:

Purpose of the Base Layer
A common problem in many Outdoor Activities is 'after-exercise chill'. Cotton T-shirts and other common underwear capture the moisture of sweat in their fabric and after your body has already cooled down and stops sweating, the wet cotton will keep on cooling your body down. Not only is this uncomfortable, it also forces your body to increase its heat production and it increases the chances of under cooling. The base layer should not retain moisture but transport it away from the skin, thereby countering 'after-exercise chill'.

Base Layer Materials
The materials used for Base Layers change constantly as manufacturers come up with new high tech synthetic fabrics or re-invent older materials like wool. In general, they all have common characteristics:

  • The materials absorb only a very small percentage (< 1%) of their weight in moisture. In practice, this means that they retract moisture from your skin and dries very quickly.
  • The fibers are very lightweight but very durable.
  • They are treated to decrease the tendency of base layers to itch and smell due to body odors and/or fungi.
Insulation Layer

Insulation Layer

The Insulation Layer is the second layer of clothing which is put on after wearing the base layer. The purpose of the Insulation Layer is to retain body heat and the best way to do so is by creating a layer of still or dead air around your body. This still air will seriously decrease the heat exchange between your body and the outside world.

Fleece / Bunting / Pile
The Insulation Layer mostly consists of polyesters that are treated in a way that makes the fibers stand up and trap air between the fibers. This trapped air forms the protective layer of still air forming the main insulation. The most popular materials are:

  • Fleece
    Fleece is mostly made out of polyesters. A dense knit of polyester fabric is taken and passed through a 'napping' machine. On one side of the fabric, the machine will pick out and rake up the fabric loops, creating a fabric with a tight solid weave on one side and a fluffy air retaining surface at the other side.
  • Bunting
    This is fleece that has been 'napped' on both sides, creating a tight solid weave with wooly air retaining at the surfaces on both sides.
  • Pile
    This is single-sided Fleece that has undergone more 'napping' and has been processed further to create a much thicker open fabric.
Characteristics of Fleece / Bunting / Pile
Fleece, Bunting, and Pile combine a few characteristics that
make them so suitable as Insulation Layer materials. First of all, they posses the ability to retain still air which insulates and prevents body heat loss as outlined above. Besides this, the treated Polyesters used have almost the same moisture-transporting qualities as Base Layers. They transport moisture to the outer layer and dry very quickly.

Outer Shells

Outer Shell The Third and final Layer in the Three-Layer System is the Outer Shell which is the only layer with direct contact to the outside world. The Outer Shell serves three main purposes:

  • Protection from wind and outside moisture like rain and snow.
  • Getting rid of body moisture
  • Protection from chafing, cuts, scrapes, and other outside damage.
Before high tech fabrics were developed, these purposes were performed by separate pieces of clothing. Nowadays, however, Outer Shells can be waterproof, shock-absorbing, and breathable windbreakers or outdoor jackets.

Outer Shell Materials
The theory behind Outer Shell materials is the fact that a water drop is much larger

in size than a water vapor molecule. In essence, combining waterproofness with breathability boils down to finding a membrane with a pore size much smaller than a water drop but much bigger than a water vapor molecule. In 1976, Gore-Tex was developed which is a membrane of a petrochemical polymer called polytetrafluorethylene (PTFE). Since 1976, many variations of Gore-Tex have been developed which fall under the category name of PTFE laminates.

Judging Waterproofness
Keeping outside moisture out is probably the most important task and, unlike breathability, waterproofness depends on more than just the fabric. Here are some guidelines on judging waterproofness:

  • The most important factor remains the fabric. As explained in our section on Tent Characteristics, the waterproofness of a fabric is measured in pounds per square inch (psi) of water pressure. Standard ISO 811 signifies the testing of the waterproofness of fabrics under their actual usage conditions. For an outdoor clothing Outer Shell, a score of 40 psi would signify a good state of waterproofness.
  • Seams - Just like inOutdoor Tents, seams are the vulnerable spots in Outer Shells. Seams should be sealed and coated well to prevent leaking. If possible, look for as little seams as possible and avoid seams in vulnerable places such as shoulders and upper back.
  • Zippers - Zippers are another weak point in your defense against moisture. Nowadays, waterproof zippers do exist so ask around. Otherwise, look for zippers that are well-shielded.

Using this Three Layer System gives you the best possible protection from outdoor conditions. At the same time, the system is flexible enough to change specific parts for better, worst, or specific conditions. In most cases, the Three Layer System pertains to upper body clothing. The torso and neck area are the most important things to insulate as they protect your body core. In extremely cold conditions, however, this Three-Layer System can be used for full body protection.

Users who read this article also read the following articles:

Find out more about hiking here in our info section

See related products in our Hiking Shop:

advertisementadvertising info

 Print Article        Comment on Article        Write New Article      
Article Comments
Dieter Brenner
Sunday 7th June 2009 at 10:56:24 PM  

Very handy to know. Also, the color of the clothing we wear can be something to consider. For example, dark clothing won''t necessary make you much warmer on a cold, cloudy day. But when the sun comes out it can be burning hot because it absorbs the heat more than lighter colored clothes

Sunday 6th December 2009 at 11:52:59 AM  

I am reading these articles and they are great . I am wondering however, can al you information on hiking and hiking clothing (i.e. 3 layer system) be applied to all hiking ? I am doing a Machu pichu hike in peru, and i am wondering do you have information in hiking in warm climates?

Also, i been wondering if ther is such a thing as hiking gloves or rock climbing gloves i can get to protect my hands from rough harsh surfaces of wilderness and rocks?


Monday 25th January 2010 at 12:54:12 PM  

im still looking 4 another 3 layer system cheaper than Gore-tex. And which variations of goretex that suitable for tropic country ? I live in Malaysia

Ching Wong Big Weena
Wednesday 25th January 2012 at 2:54:31 PM  

Oh Ya dass cool me need more rice and good clothing for climbing mt everest, me wondering if you have balaclava for chinese man

Post A Comment

Name: (required)

Email Address: (will not be published) (required)