Dressing for a winter hike is part art, part science, and all survival skill. It's also the key to staying comfortable on -- and thus enjoying -- a cold-weather outing. Even if it's not full-on winter yet, you can still apply the same basic layering principles to any cool-weather adventures.
Layered clothing serves three purposes:
- Keeps you warm when at rest
- Keeps you warm but not overheated when you're exercising (and thus generating extra body heat)
- Makes it easy to adjust your insulation between those two extremes.
You need more insulation to keep your body warm when you're at rest, but as you start moving you can remove extra layers of clothing to keep from overheating. The key is to remove those layers before your body activates its built-in cooling mechanism (sweat). Sweat can drench your inner layers, reducing their insulation value; the damp fabric is also very uncomfortable against your skin.
Think long underwear. This first layer should fit close to your skin, but not so tightly that it impedes your movement or circulation. Avoid cotton -- which holds water and loses its insulating ability when wet -- and aim for wicking synthetics or wool, both of which will help keep you dry (and warm, even when wet).
I personally prefer wool over synthetics whenever possible, especially when it's going against my skin, because my body chemistry causes synthetic fabrics to start stinking quickly.
Wearing skivvies under your long underwear is optional, although if you're on a long backpacking trip I recommend it for the sake of hygiene. Once again, steer clear of cotton and opt for wicking synthetics or wool instead.
- Yes, even something as innocent and everyday as cotton underwear can contribute to hypothermia. Nature has no modesty, and will take fullest advantage of your choice of undergarments.
- Yes, they make wool underpants (and bras). You can buy them in most sporting goods stores.)
You should still be choosing wicking fabrics (synthetics or wool) for this layer. Your insulating layer is usually thicker than your base and primary layers, although if the weather is relatively mild I may just carry an extra, slightly larger and heavier, pair of long underwear as my insulating layer. It's important that this layer be a little bigger than your base layers so that you can move comfortably, but it shouldn't be so large or heavy that you feel like a yeti.
This is the layer you're usually going to take off once you start moving, and then put back on once you stop moving and your body starts to cool down, so a full-zip closure is ideal: It's quick and easy to get on and off. Buttons all the way up and down the shirt are your next-best option, followed by a half-zip. I recommend avoiding pullovers if at all possible because they're so hard to get in an out of, but if you're strapped for money, you can make do with all-wool sweaters (which are usually pullovers) from a thrift shop.
Weatherproof Layer -- Upper Body
Good-quality jackets tend to be pretty pricy, so I wouldn't mess around with a hoodless, water-resistant, wind-resistant soft shell, which is only useful in a relatively limited set of conditions. Instead, spend your hard-earned money on a waterproof, windproof and breathable jacket, with a hood that fits well, leaves room for a hat, and doesn't obscure your vision. This type of jacket will serve you well in even the worst conditions, but can be zipped open for extra ventilation (or just taken off) when the weather's mild.
Other features to look for: Armpit zippers for extra ventilation, and sleeves long enough to cover the cuffs of your gloves (even when your arms are bent, which tends to make your jacket's cuffs creep up your arms). The hem of the jacket shouldn't ride up when you lift your arms over your head.
Weatherproof Layer: Lower Body
For some reason it's pretty common to think that just because you've got a weatherproof jacket on, your lower half is going to stay warm and dry too. That's definitely not the case in driving wind, rain, or snow, all of which can easily crop up during a winter hike.
Like a good shell jacket, good-quality weatherproof pants (read: the kind that are actually comfortable enough to wear and hike in) tend to be expensive, so I recommend investing in one waterproof, windproof, and breathable pair of pants that fit you well. Features to look for include thigh zippers for ventilation; zippered ankles for extra ventilation and to help you get the pants on and off over your shoes or boots; or in a perfect world, full zippers up the sides of your legs that serve both purposes at once.
Now that you've got your body covered, it's time to dress your extremities for the cold. Also, did you know that cold weather can affect your camera, too?