It doesn’t matter how good the rest of your clothing system is. If you have cold feet you are having no fun, and if they get really cold your trip is over. The one area we violate our rule about total breathability is for boots. Its complicated (read on), but there is also a full breathability option, but with more risk for wet feet if encountering slush and overflow, or melt down conditions. There are two main snow boot types for winter camping and trekking: Pac boots and mukluks. And then there are back country ski boots. I won’t be covering arctic sealskin mukluks or other native crafted mukluks or moccasins. If you own and use these, then you likely already know everything in this next section. For most people these authentic mukluks are not an option so we sill stick with the most commonly available.
These are the most commonly used boot and almost everyone has a pair at home – they are the boots with the felt liner. They typically have a rubber bottom, and either a nylon or leather upper. But all pac boots are definitely not created equal.
After using many boots, I and my buddies are convinced that the extra insole in the bottom is the key to warm feet in pac boots. The boots need to be designed to accommodate that – you can’t easily just put one in a regular boot because the boot fit will become too tight. Most models do not have this feature. You can tell by looking at them. The ones which have it have the high looking toe box, and the ones without are flatter. You can get by with the regular boots, but if you have cold feet problems, the extra insole design is the way to go. The slight down side for the larger toe box boots is that its more difficult to fit into a standard snowshoe binding. But with some minor binding modifications it’s a straight forward adjustment.
Take the manufacturers temperature rating with a big grain of salt. Everyone’s circulation and physiology is different. There is one universal constant though for warm feet in these boots: You have to be able to wiggle your toes with your sock system to the max. If you cannot wiggle your toes, get a boot size bigger until you can. Bring your sock system into the store when trying boots on. No matter how thick the felt liner, you will need a robust sock system. I mentioned mine above in the Base Layer’s section. It’s not the end of the world if you bought a size too small and used them and now can’t return them. It’s happened to us all. Go back and get a bigger pair. Pass the too small boots on to someone who needs them and you have done a good deed.
I prefer the leather upper models because I like to be able to lace them up for a firm grip for no foot slippage. But all boots can cause blisters, so always bring your blister kit just in case.
When you find the boots you like, be sure to buy an extra set of liners. On the trip, bag the liners in a waterproof bag. These are your emergency replacements if you get a soaker, and they are also the regular replacements when you dry out your boot liners anyways. I have found you can go two days before your boot liners are absolutely soaked. If you can, dry them daily. In a hot tent its easy. Cold camping it’s a challenge. If bright and sunny and low humidity, your liners will dry out in the sun and wind. Add a loop of cord to the backs so you can hang them on branches. If its dull, snowing and grim while cold camping, you can rig a drying rack by the fire and turn them to get them more or less dry enough. Some folks wear them to bed in the bottom of the sleeping bag to dry. It will transfer moisture to the bag though, which can lead to a frost build up when cold camping.
Modern felt liners in high end pac boots are very absorbent. So much so that in my boots my socks are relatively dry at the end of the day, despite the fact my felt liners may be soaked. I go to bed with my day socks on. There’s no need to change them. I will be discussing this issue of what to wear to sleep in the Sleeping Systems section.
Vapour Barrier Socks:
I have never tried these, but some people swear by them. They are liner socks which contain all your foot’s moisture. The theory is that once the sweat reaches a certain level, your foot skin cells respond by shutting down the sweating since there is enough moisture being sensed. You wear one thin sock against your skin which does get wet. The next is the VB sock. Outside of the VB are your insulating socks. The result is that your insulating socks and felt boot liners never get wet. You change the inner sock daily and dry it, which is easier because its thin.
This is not just theory – its practiced by many expedition level trippers. Your results may vary. There are some skin health issues to test out however, and you will only know by experimenting. Before you buy a commercially available vapour barrier sock, you can rig plastic bags to check out the effect. Personally I have my doubts for the way my feet work, but one of these days I will have to experiment and report back.
The true leather and canvas mukluks have no synthetic or rubber barrier to transmitting moisture like pack boots do. Commonly available mukluks have an uncoated leather lower with a crepe rubber sole for durability and traction (the one small area of moisture impermeability), and a cotton canvas upper for maximum breathability. Their advantage is twofold: (a)Your feet and toes flex more, staying warmer, and (b) the moisture build up is far less than a pac boot, and you might never have to dry out the liners in the field.
They have proved themselves on major expeditions in extreme conditions, and work very similarly to traditional moccasins which kept people’s feet warm for thousands of years.
I have a pair but have yet to fully put them through their paces. The disadvantage of mukluks is the direct opposite of their advantage: They are not waterproof. I travel on lakes and there can be nasty slush problems where my pack boots have many times taken the plunge in several inches water, but kept me dry. If you don’t know what lake ice slush and overflow are, we will be positing an article on that soon. Pac boots also provide more support to tender feet that grew up in hard soled shoes and boots. However you can use supportive insoles in mukluks to compensate for their softer sole.
Back Country Ski Boots:
We will be discussing BC ski boots in more depth in the Back Country Ski Section. But I will mention them here regarding basic warmth information, since we are talking about boots in general.
Hauling sleds and toboggans with back country skis, when the snow conditions allow for that, is a great joy. My buddies and I use skis whenever possible. We spend a good part of the day in ski boots, and keeping feet warm on very cold days is challenging.
There are heavier touring and light telemark or mountaineering plastic boots with thicker synthetic liners, and there are lighter touring leather or light leather/fabric/plastic ski boots. I use and know more about the latter so will be referring to them.
These leather ski boots have little insulation, so most of the warmth comes from your sock system. I have skied at -35 (when the snow is like sandpaper!) and believe me you need to be able to stuff several sock layers into those boots. (See Base Layers above for my sock system). Thus you have to usually size the boots up half a size. Boots to tight will be freezing. It’s better to have them a little too big than too small. Too big can be altered and filled.
You wear gaiters to keep the snow out, and to thwart an accidental quick in and out plunge into slush.