Not wearing proper clothing or layering correctly while traveling in a snow-laden environment could lead to cold injuries and death. As a survival instructor for the military I find myself in these environments often and teach others how to effectively travel in them. In the lists below I will note the things that I typically wear and why.
I follow the basic principle of wicking, warming and weather layers. The purpose of the wicking layer is to keep moisture from accumulating on the skin and to allow it to evaporate if at all possible. Above this we wear a warming layer. This is the layer I’m going to remove depending on the amount of work I’m doing to ensure that I don’t sweat. Finally, we have our weather layer. This layer will typically be on at all times as I don’t want to get the under layers wet. The layers I usually wear when instructing are a Patagonia or Crye combat shirt as my wicking layer, Beyond Clothing A3 Alpha Sweater as my warming layer and a Beyond Clothing Wind Shirt or a Beyond Clothing A6 Rain Jacket depending on precipitation as my weather layer.
In weather above 15 F I wear no thermal underwear and wear either Crye Field or Crye Combat pants. If the weather drops below 15 F I may opt for thermal underwear in addition to the Crye pants. I find that I tend to sweat too much if I wear thermals in weather above 15 F. Another consideration is also the amount of precipitation that you have. If the temperature is hovering around or near freezing and the rain is staying rain, you find yourself in a very dangerous environment. This is what we call “prime hypothermia weather”. In environments such as this I’ll opt for a full Gore-Tex ensemble of Beyond Clothing A6 Rain Jacket and Rain Pants.
The shoe and socks makes up perhaps one of the most crucial pieces of the picture. If your feet sweat too much you’re likely to sustain a cold injury of some type. I’ve seen multiple approaches but in my experience I’ve found what works best to be one pair of quality thick socks such as winter weight smartwool socks (or equivalent, darn tough are great as well) with some type of full grain leather boot and gaiters. The reason I recommend one pair of socks is that if you begin to layer socks to try to keep your feet warm it ends up doing the opposite. With 2-3 pairs of socks on, your feet have less room in your boot. This compresses your feet and reduces blood flow. As blood flow slows within your feet you’ll find yourself much colder than you need to be. Hence, wear one good pair. You can mitigate this by getting a larger boot size, but I prefer the one sock approach.
When it comes to boots I prefer to use a full grain leather boot. I find that they last longer than synthetic boots and can be treated easier. Before every outing I heat the leather on my boots using a hair dryer and apply as many coats of SNO SEAL as I possibly can before the leather stops absorbing it. SNO SEAL and other weather proofing waxes stop water from soaking into the leather and lead to dry warm feet. The waxes also treat the leather and helps keep it supple so that it doesn’t crack. The boots I personally use are either the Asolo TPS 520 GV for snow no deeper than 2 feet, or in more extreme weather the Kenetrek Mountain Extreme 400 insulated hunting boot. Don’t lace your boots tight, if your boots are overly tight you’ll restrict blood flow to your feet and your feet will be more susceptible to cold injuries.
The aforementioned boots are always paired with gaiters. Myself and many others typically roll with the Outdoor Research Rocky Mountain High Gaiters. Gaiters will mitigate the amount of moisture that soaks into your pants which could in turn soak your socks and then your feet. I wear gaiters in most environments and even if not I keep them in my pack as they weigh almost nothing and pack down quite flat.
I realize I’m throwing out some high dollar equipment. This is not a comprehensive list of winter clothing but rather what I use. There are many other excellent companies out there that make warming, wicking and weather layers. Arc’teryx and REI come to mind immediately. You can definitely get what you need for less. I’d feel irresponsible if I didn’t mention that you should always have emergency equipment on you in a winter environment. Tinder kit, signaling devices, and ways to collect and purify water are essential.