There have been a lot of reasons that I have not posted to my blog for a while.  I am an ardent conservationist and environmentalist and much of what I see happening today, from our reluctance to admit and address what is happening with our climate, to the reduction, and inappropriate use, of our public lands for the immediate and selfish gain of a few, I find not just alarming but extremely discouraging.  I thought we, as a country, were better than that and that we could never turn the ignorant or arrogant eye that we now do daily.  This has kept me from blogging because I do not want to pontificate, as I unfortunately just have, about all the environmental wrongs that I see continually occurring.  Today, instead, I thought, perhaps I could start a series of more technical blogs and I apologize now for the brief trip down the I-don’t-give-a damn-about-what-we-leave-environmentally-for-future-generations rabbit hole that I have just taken.

Winter hiking is an experience that is unparalleled in all that we do outdoors.  There is a stillness in the winter woods that you will never find any other time of the year, and the mantel of snow that covers everything makes trails smoother and often easier to travel.  Small streams and brooks are frozen over making them easier to cross, you can see further through the trees without all the foliage, and the forest floor has more direct and reflected light.  When the sun shines, the woods sometimes sparkle with the refracted light of a million little snow and ice crystals.  It can be breathtaking.   There are, of course, exceptions to the ease of traveling snow covered trails (the major exception to this would be trails that have unconsolidated snow such that you might find right after a very heavy snowfall), but for the careful winter hiker in the Whites, who plans their trips well, the dangerous conditions can be avoided and they will be rewarded with nicely packed out trails that are often easier to hike than during the warmer weather.

Exploring the wilderness in the winter, however, does take some training and the proper preparation. It is cold out there, sometimes very cold, and to be safe one must dress appropriately.  Before we discuss clothing, let’s review the science of how one’s body loses heat in the winter.  There are four ways one loses heat:  evaporation, convection, conduction and radiation.  Evaporation is the loss of heat through the evaporation of sweat and moisture through the skin, mouth, nose and lungs.  As water evaporates, it changes state from liquid to gas which takes energy or heat.  That heat, called the latent heat of vaporization, comes, in this case, from your body.  The net effect of evaporation is that the surface upon which the water evaporates, becomes cooler from this loss of energy.  Conduction is heat that is lost through direct contact with something cooler.  In hiking, conductive heat loss is primarily through contact with the moisture in wet clothing.  Different substances have different rates of conductivity and, while fabric has a very low rate, water has a very high rate.  Convection is the loss from wind blowing away the thermal layer of warmth that surrounds our bodies and when we consider this type of heat loss, we are most often thinking of this in terms of wind-chill.  By far, however, the greatest means by which the body loses heat is radiation and it can account for as much as 60-65% of our heat loss in the outdoors.  This is the loss of what people think of as body heat, and comes directly from our skin and our head.  This heat is the results of our vascular system carrying oxygen rich blood from our warm core out to our cold skin, providing oxygen to our cells but losing heat in the process.   Successful winter hiking clothing schemes address all four of these heat loss areas.   

As a hiker you are active and exerting energy, which is different than, say, a snowmobiler who is out in the cold but sedentary.  It is also different than an ice climber who may stand in the cold for hours on belay while his buddy climbs.  While these may all be outdoor winter activities, they all require different clothing systems.  When we are active and working hard, such as we would be while climbing a mountain or cross country skiing across a valley, our body’s tendency is to sweat.  Sweaty or wet clothing immediately begins to break down our cold weather clothing system and it is the primary reason by which people get chilled while in the outdoors and begin to move towards a hypothermic state.  Our goal, therefore, is to provide the outdoor enthusiast with warm, comfortable clothing, while keeping them from becoming so warm that they sweat when they exert themselves.  We cannot stop sweating entirely, so what little sweat does occur, must be moved away from the body quickly so as not to contribute to conductive heat loss. 

Let’s stop here a minute, though, and mange expectations.  One cannot simply get dressed in “appropriate winter clothing”, prescribed by me, or by anyone, and expect to be warm and dry all day long. Any winter clothing system will require management and must be flexible and capable of adapting to different conditions and different states of exertion and it takes work on the part of the end user to recognize when it needs to be adjusted.  The goal is to actually stay just a little chilly.  When one starts to warm up, layers are changed to keep the wearer on just the cool side of warm.  Activity should be steady and starts and stops, as well as periods of great exertion, should be avoided.

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All systems must start with a base layer.  Underwear is not a base layer.  If you count yourself among those that prefer to wear underwear beneath a base layer, the same rules for a base layer will apply to underwear but underwear does not replace the latter.  Your base layer is the layer closest to your skin and the primary purpose of this layer is to wick away moisture.  This layer should be thin and made of fibers that are good at, or design specifically for, moving moisture away from the body, or “wicking”.  Many wear wool or silk base layers, but there are a large number of synthetic fibers that are specifically designed for this purpose and may perform better than these natural fibers.  The primary material used in these products is polypropylene, an extruded plastic product, but manufacturers have a number of proprietary extruded shapes, and differing claims as to how well they wick moisture, so this may be found under other names.  The primary point of these materials is that because they are plastic, they cannot absorb moisture and, through capillary action, no matter what the weave or shape of the fiber, the laws of physics show that they will move moisture away from the body. 

Base layers should consist of three pieces, a shirt for your torso, long pants and socks.  Again, if you wear underwear, a base layer goes over your underwear.  A mistake that is often made is that hikers will have good polypropylene base layers but they have cotton underwear or a bra underneath.  There is an expression among outdoor enthusiasts about cotton; cotton kills.  Cotton absorbs moisture and keeps it close to the body instead of wicking it away.  Avoiding cotton clothing entirely is a practice that will serve a hiker well in any season.

The next layer is an insulation layer.  This layer must allow moisture to pass through it, but must retain one’s body heat.  Here we are trying to minimize the loss due to radiation.  Since the addition or removal of insulating layers is how one manages their warmth, I prefer to go with two thin insulating layers rather than one bulky one.  Polar fleece, wool sweaters, synthetic or down quilted shirts, sweaters or jackets are all good insulating layers, but if you have just one thick layer, and you begin to overheat and need to remove that layer, you are left with no insulating layer and may begin to chill. Knowing that is their only choice, hikers with a thick insulating layer often forego removing their insulating layer and then they end up sweating; a recipe for disaster when you are miles away from the trailhead.  Some people like to have a thick and a thin layer in their pack and they wear the one that is most appropriate for the activity they are doing.  This is a fine strategy, however, when they change from one layer to the other, they temporarily lose the heat that has been transferred to the old garment through convection and conduction and it will take both time and energy to warm up the new layer.  Again, I prefer two thinner insulating layers instead of one bulky layer.  Also, when assembling your clothing system, consider how easily the layer will be to remove; a layer that comes off with a zipper or buttons down the front will be easier to change than one that pulls over the head.

For pants, I often wear a pair of tights or leggings over my long underwear, but choose wisely here so as not to overheat your legs.  For your feet, over the light base layer socks mentioned earlier, you should wear a pair of wool socks or synthetic blend socks.  Again, no cotton.  We will have another post eventually on boots, but for now let me caution you not to overcrowd your feet inside your boots.  Insulation involves layers of dead air space or trapped air through which heat cannot pass.  If your feet are jammed into your boots because you are wearing the pair of super ultra thick wool socks your grandma gave you at Christmas to keep your feet warm, your feet may actually end up being colder than they would have if you had used a normal pair of wool socks.  Sorry, Grandma.

On top of your insulation layers you need to wear an outer protective layer.  Next to your base layer, this is your second most important layer.  Like the other layers, this outer layer has to provide for the movement of moisture to the outside, but this layer now has to protect you from wind (convective cooling) as well as from precipitation.  The best outer layer garments are made of Gore-Tex or some other waterproof and breathable material; look for these.  I would recommend a jacket with a hood, since above treeline, hoods are very good at protecting the head from wind chill.  You should wear a wool or synthetic hat, but wind can strip away the trapped heat between the fibers of these hats and a hood can prevent that heat loss when the breeze picks up.  I sometimes wear a softshell jacket on top of my insulating layers, but then carry a hard shell in my pack.  When I get above treeline, or when the wind picks up, I can pull out the hardshell and put it on to protect me from driving wind or precipitation.  When I am not above treeline, the higher level of transpiration of the softshell allows for better movement of moisture from my body outwards.

I always wear Gore-Tex pants.  Some people prefer to purchase insulated winter hiking pants, combining the insulating layer with the protective outer layer, but again, my preference, is always to have the flexibility of individual layers rather that thick combined layers.  What is of primary importance is that pants should be waterproof.  You will sit in the snow, glissade or butt slide down trails, etc., and nobody wants a wet ass- nobody.  Also, some practical pointers about pants...  Since it is important to keep yourself hydrated while hiking in the winter (remember about evaporative heat loss from the skin, lungs, mouth and nose) it is only natural that you will have to relieve yourself from time to time.  Make sure your lower garments allow for this.  This is particularly true for those that like to wear bib style pants.  Bibs are great for keeping your lower back covered, but one must consider how difficult it may be to step off the trail and go to the bathroom and what will be required to do such when the time comes.  The large seat-of-the-pants zippers may work great on the ski outfit in the ski lodge bathroom, but they are not as easy to negotiate at five degrees, on the side of the trail, with a pair of mittens.  Also, consider, if your legs begin to get hot, how easily you can let some heat out of your pants .  My personal preference is to wear mountaineering pants with full zippers that run down the outside of both legs.  These types of pants can be unzipped in varying amounts to regulate the temperature of my legs if they warm too much.

As I said earlier, we will discuss boots another time, but in this post we should emphasize that it is important that whatever boots you end up using should be waterproof.  If your feet begin to get wet on the trail, there will be little you can do to warm them up, so keep them dry to begin with by using waterproof boots.

There are a few more accessories that should be mentioned before we end this post.  Everyone should always have a good hat.  I keep a wool hat in my pack year round, but in addition, in the winter I use a nice wool or synthetic hat that will cover my ears and keep my head warm.  I do not hike with a scarf but instead prefer to use a neck gaiter when it gets really chilly.  Neck gaiters keep a lot of heat in, so I do not wear them all the time, but they are nice to have when it gets really cold.  Likewise, on cold summits, I sometimes use a balaclava over my head and around my face to help minimize skin exposure to the wind.  Be careful of balaclavas that cover your nose and mouth since they can get wet in these areas quickly from respiration and runny noses.  Wet balaclavas freeze quickly and while it sometimes cannot be avoided, one should at least be prepared for it and try to purchase balaclavas that are designed to mitigate this result.

On my hands I wear double layer mittens, and under the mittens I wear glove liners.  Mittens are only so dexterous and there are plenty of times I need to snap a buckle or grab a zipper or something.  In these instances, removing my hand from my comfy mittens is tremendously better when I am wearing thin glove liners than when I am not.  They are worth the ten dollars they cost and then some.

So that about wraps up this post on winter clothing.  Still to be discussed in future posts are boots, traction, cold weather drinking and fueling, and how to get the most from your winter excursions.  Hopefully those posts will not be quite as long as this one has been.  Thanks for hanging with me.  Go get a cup of hot chocolate, grab a trail map, and start to plan about your next winter adventure.  Oh, and go ahead, take your shoes off and put on Grandma’s socks.