Wise Weather Wears: how to dress smart!
The secret to cold weather dressing is comprehension of the heat-loss mechanisms and
knowing how to use layers of specific materials to combat them. The different clothing layers
act as a team to fight against the wind, moisture, and the cold and allow the wearer their own
“thermostat,” so to speak – they are able to adjust their temperature by adding or removing
layers as needed depending on their conditions and activity levels. Our clothing holds onto the
body heat which we are constantly releasing through radiation, so the better it is at retaining
this heat, the less our body needs to work and burn through calories to produce more.
Evaporation takes heat energy from our bodies to convert liquid water to gas as we dry.
Convective heat loss occurs when wind or water pulls your heat away from you. You lose heat
through conduction when your warm body comes into contact with something colder as it will
begin to heat the cold object. These mechanisms are simple and require simple strategies to
control. Cold weather activities become a lot more fun and safe when you know how to dress.
Know your clothing’s ingredients: wool? cotton? polyester?
Hydrophillic: water loving fabric – tends to soak up and hold onto moisture. “Cotton kills” is a
term well known among outdoor sport enthusiasts. The body loses heat 25X faster when wet
due to evaporative and convective processes which attempt to steal your heat. Wearing cotton,
a natural fiber which holds onto your sweat and dries very slowly, can be deadly in coldweather scenarios once you stop moving.
Hydrophobic: water hating fabric - pulls moisture away from skin and spreads it out to assist
with drying. Polyester and polypropylene are good examples of hydrophobic fabric. The faster
you can push the moisture away from your skin, the better.
Base layers are moisture-wicking
underwear layers (hydrophobic
material). In cold weather, wear a
base layer over your upper and lower
body, feet, and hands. This layer will
pull moisture from your skin, spread it
across the material to assist with
drying and push it through into the
insulating mid-layers which will allow
it to exit through the outer shell layer in the form of water vapour.
Mid layers are insulation layers. These layers trap your radiant body heat within tiny pockets of
dead air space. Imagine a shirt of bubble wrap: your body heat warms each bubble of air and
allows the warmth to stay near your body for longer. If you pop the bubbles, your body is back
to warming the environment around it. A mid layer of hydrophobic material such as polar fleece
can be nice and warm yet further facilitate the movement of moisture away from your body.
Wool is the best insulation for outdoor recreation. Being a natural fiber, wool can hold onto
moisture for longer, but wool has the remarkable ability to maintain 75% of its insulation value
when wet. So a wet wool sweater still out performs most other fabrics (cotton loses almost all
insulation value when wet, even if the garment is very thick, fluffy cotton).
Outer layers are your protection against the elements. This layer acts as a cap to seal in all of
your radiant heat while keeping water and wind out. Zippers and vents help facilitate water
vapour release while higher-end materials such as Gore-Tex facilitate water vapour release
through the material itself, almost like a second skin. Nylon is a great shell material, especially
when stitched in a cross-hatched formation to make what’s called rip-stop nylon; if it does get
ripped on branches or barbed wire, the hole won’t get larger. There are many water-proofing
treatments and water-resistant materials, but they all come with different price points and
durability ratings. People get by with less than they expect they may need if they have all other
layers properly thought out. High price doesn’t always mean it’s the best!