Winter Underwear - Arctic / Antarctic, Cold Weather, Thermal Clothing
The base or foundation layer is worn next to the skin, for cold climates this is "thermal" underwear.
The layer of clothing next to the skin has two jobs to do, the obvious one of keeping you warm and then the equally important but less obvious one of removing perspiration from the skin so it doesn't cause chilling later on.
In cold temperatures perspiration can be more of an issue than in a warmer climate. The skin loses moisture at all times whether undergoing exertion or not. If there are overlying insulating layers keeping you warm, it is more difficult for this perspiration to escape, If it is not removed it will result in the wearer becoming uncomfortable with a feeling of clamminess as well as lowering the efficiency of the insulating layers.
Underwear that is able to wick this moisture away from the skin surface therefore becomes much more important. Modern "thermals" are made of natural merino wool or synthetic fibers such as polypropylene and "fleece" that have good insulating properties and are also able to efficiently wick moisture away from the skin. The golden rule is to avoid cotton except in some very specific situations.
Features of the foundation layer
Which material for your
There are a number of materials commonly used for the foundation layer, each has its advantages and disadvantages:
- this has become the gold standard material
for the foundation layer, as you may suspect
from this, it is not the budget option but it does deliver
on performance. It is simply the wool of the merino
sheep, a particularly soft and fine natural product.
Merino wool garments deliver significant warmth with
light weight, they are very good at wicking sweat away
from the skin surface and so are particularly effective
in use during exertion. They are also odor resistant
and so can be worn for extended periods without changing
or washing while still making you someone that others
still want to be near.
Men's merino | Women's merino
- A range of materials, polyester and polypropylene
are commonly found as are proprietary versions (brand
names) of generic fabrics. If I made my own I could
take a form of brushed polyester (say) and call it CoolAntarcticene
for instance. Synthetics wick sweat away from the skin
very effectively, insulate well and are available in
different weights, they dry faster than any of the materials
on this page, but are not so good at being odor resistant,
but may be treated to make them more so.
Men's synthetic | Women's synthetic
- Another natural material, very thin and light
weight delivering excellent insulation for minimal bulk.
Not as effective as merino or synthetic, though silk
really comes into its own in situations where looks
matter, you can squeeze a silk layer under something
else without it being noticed or where a matching or
contrasting patch of colour enhances an outfit. It is
also particularly delightful to the touch. A good choice
for cold weather in the city under your office work
Men's silk | Women's silk
- A traditional, natural material but outperformed in
most circumstances by the alternatives. Cotton doesn't
wick sweat well which can make it feel cold and clammy
with retained sweat after exertion, it is also relatively
heavy and has a tendency to go a bit baggy with use,
especially at knees and elbows. It is more fire and
electricity resistant than many thermal underwear materials
which makes it recommended and in some cases the only
permitted material where these are a real hazard.
Men's cotton | Women's cotton
Merino Wool Base Layers
Synthetic Base Layers
Silk Base Layers
Cotton Base Layers
- Lightweight - approx. 170 gm2
- Midweight - approx. 250 gm2
- Heavyweight - approx. 400 gm2
Foundation layers come in a range of weights usually described as light, mid and heavy. The one to go for depends on a number of factors, your anticipated activity level, the external temperature and how keenly you feel the cold. There is also the fact that heavier weight materials will be more bulky and so require more flexibility of fit of the over-layers.