The Layering System
What it is, why it works and how to make it work for you
is all about delivering flexibility and comfort; comfort being warm or
cool as suits whilst also staying dry. For active outdoor pursuits both
need a little explanation.
Wearing layers of clothing rather than
one chunky jacket allows you to adjust how much you’re using quickly
and easily. It means that by shedding a layer or two and opening zips
for ventilation you can avoid overheating slogging up a steep hillside.
When you reach the top, replacing the layer/s means you won’t get
The layers – next to the skin or baselayer, mid layer
and outer - work together to deliver aspects of comfort other than just
wrapping up warm. Modern synthetic fabrics are quite sophisticated in
the way they work with your body – different weights in thermal garments
offer warmth options whilst others are more suitable for highly aerobic
activities where lots of body heat is being generated. Our bodies are
always giving off moisture vapour just by breathing and expending energy
always generates heat; we avoid overheating by sweating.
work in a layering system by not absorbing sweat nor allowing body
moisture vapour to condense into liquid but instead let both through the
fabric unhindered to then pass through the insulating mid and
wind/waterproof outer layers to be dissipated in the atmosphere.
Windproof/waterproof outer layers help to conserve body heat trapped in
the layers underneath and, by being breathable, avoid condensation
forming and soaking clothing.
The performance of modern layering
systems and fabrics is probably best understood by wearing a cotton
t-shirt under a non-breathable jacket and powering uphill. Before long,
the t-shirt will be soaking wet and condensation will be running down
the inside of the jacket. As the moisture evaporates, it will draw body
heat away, chilling you and, of course, being potentially dangerous,
especially in the mountain environment.
So, flexibility and the
many faces of comfort are central to the purpose of a layering system.
As the wearer, it’s up to you to manage body heat retention and loss to
suit yourself, your activity, the weather and the outdoor environment.
It’s not a static system but works interactively with all those factors.
elements of any layering system are hats and gloves as they are the
most flexible to shed or add and have an almost instant effect on
cooling down or warming up.
– warm or cooling options both allow moisture through rather than
soaking the fabric, chilling the body and feeling very uncomfortable;
both options aim to avoid the feeling of clammy skin.
– essentially offering insulation by trapping air warmed by body heat
but not absorbing moisture and becoming wet. Natural or synthetic
materials and fills are available in a variety of styles and warmth
Outer layer –
protecting the underlying layers from wind, rain and snow, breathable
fabrics ensure moisture can be transferred to the atmosphere rather than
accumulating on the inside