Dressed for Success
08/26/2008 9:38 pm

By: Chad McDonald, SNA Operations Mgr/Field Producer

When it comes to topics of much debate and opinion, “What is the best way to stay warm in the field?” ranks as high as “which is better fixed blades or mechanicals?” and “what is the best all around caliber?” I have put together this article to help outline some facts about heat loss and conservation that will hopefully help you decide on what gear to wear out into the field this fall and winter.

I have found that rather than “staying warm” I would rather “stay comfortable”. I realize that this often means one in the same when out in the field but in actuality being too warm can be a bad thing. Hunting seasons open up all over the country in September and along with the variety of game can also mean a variety of temperatures to go along with it. Are you going to be sweating it out all day in a ground blind after antelope or in a grain field hunting dove under the sun? If so then light weight cottons, a base layer that wicks and plenty of water should be all you need. Or are you going to be chasing elk or mule deer in the high country where it can go from sun to snow overnight? And then we’ve got long sits in the whitetail woods to think about where seasons and temperatures can range from relatively mild to downright “what the heck are we doing out here” cold. To understand how best to dress we should first look at how we loose heat.

Heat is lost in four ways; conduction, convection, evaporation, and radiation.

Conduction is simply the movement of heat from a warmer object to a colder one when in direct contact. For example, that big rock you are sitting on that has been chilling overnight is actually sapping heat away from your body through your rear end, making the rock warmer and your body colder. Of course this can work the opposite after the rock has been baking in the sun all day but all-in-all, I prefer to sit on the ground, a little better insulator of heat. There are three factors that affect the amount of conduction that takes place; 1. The temperature difference between the two objects in contact with one another. 2. The amount of surface area in contact with each other and 3, the effectiveness of the material between the two. Long story short, sit on a pad when possible and alternate from sitting to standing if possible.

Convection is similar to conduction only the two objects are moving in relation to one another. For example, you are sitting still, the wind is howling, your exposed face gets cold OR there is no wind but that ride on the four-wheeler created a heck of a chill. Most of us have to deal with the wind blowing while we are relatively still so the best way to combat loss of heat through convection is by making your outer layer a wind proof AND insulated layer (if possible) thus blocking the wind rather than having it rob the warmth created by your insulating layers. More on that later.

When water evaporates, its change from a liquid to a gas on the surface on which evaporation occurs can cause a great loss of heat. Obviously in a hot environment, wetting our selves down can be a welcome thing to help keep ourselves cool but in a cold environment, evaporation can be a killer as it saps a large amount of energy and heat away from your body to be transferred to the cooler outside world. This is why it is especially important to remove layers without hesitation the moment you feel yourself heat up and even take a minute to cool back down. It is also important to do this because as your clothing gets wet, it looses a lot of its insulating value and effectiveness keeping you warm. I always wear as little as possible when walking into my stand location. Usually just my boots, pants and base layer top and then get dressed at the base of the tree. Also remember that evaporation happens when we breathe. As we breathe in cold air in, our bodies use heat to warm that air and then we exchange that heat out into the cold air through evaporation when we exhale. It’s always best to take slow shallow breaths through your nose when possible in a cold environment while breathing through your mouth in a hot environment can help cool you down.

Heat loss through radiation is basically the transfer of electromagnetic energy between two objects of different temperatures. I know, I know…”layman’s terms man!” I could go into how this works with regards of how the absorbed temperature of the earth heats the air on a cloudy day or night vs. un-cloudy, but essentially what it means for us is KEEP YOUR SKIN COVERED, i.e. face, hands head and neck.

Now that all that is solved, let’s look at clothing choices. It is pretty much a universal given that everyone should “layer” their clothing but with what? And how? To get to the bottom of this rabbit hole we have to first start with fabrics and materials.

There have been a number of advancements made in the last 30 years or so in synthetic fibers, for example Gore-Tex and Thinsulate can be found in almost any waterproofing/insulating system out there and polypropylene can be great for wicking AND insulating. All great choices in the right clothing application but there are still some natural fibers that should go in any outdoorsman’s clothing bag.

Wool, good old fashioned wool. Heavy? Yes. Itchy? Sometimes. However it is THE ONLY material that will keep you warm when wet AND it is a great material for wicking moisture away from skin. Because of these 2 factors I prefer wool socks above all others. I start with a thin poly sock first, to wick moisture into the wool sock. For those of us who wear a rubber style boot such as “Bone Dry” or “Muck Boots”, etc that do not breathe, our feet may be a tad wet from sweat but they will stay warm with wool. Gore-Tex boots are both water proof and will breathe but are usually low cut so crossing a stream or walking through snow will allow water into them as well as get your pant legs wet. Also beware of footwear that says “water resistant”. Water resistant IS NOT water proof, your feet will get wet.

Base layers (or what ever you like to call them; long johns, long handles), this is the ONLY layer other than your socks that you will wear snug against your skin. Your base layer above all else should wick moisture away. Insulation will come later and although there are some that will do both, usually the heavier weight you go with your base layer the less wicking properties it will have. Under Armor is arguably the most popular synthetic base layer on today’s market and is a great choice along with similar type base layers, however silk…yes silk…has been a popular choice for both the military as well as snow skiers for years AND it has some insulating properties as well. Either way you can’t go wrong. If temperatures are a bit more extreme I will follow this with a layer of looser fitting polypropylene.

Your next layer is the trickiest and dependent upon the conditions you are hunting. The trick is for this layer to hopefully be your final layer. While yes, we can always add a jacket later, bulky clothing can make it difficult to shoulder a rifle or draw a bow. We want to “bundle up” with out having to “bundle up”. Remember wool is always an excellent choice. It has been the anchor of hunters and trappers for centuries it can however be very heavy and bulky. My personal preference is Polar Fleece. Comfortable, warm, moisture wicking, quick drying, durable and QUIET, this fabric has changed the way hunters dress and it comes in several different weights to match climate conditions.

The formula for the outer layer is simple. It must be waterproof, windproof, and provide warmth. This is the garment that has to protect the hunter from snow, rain, and wind. A Gore-Tex jacket will take care of the water and wind proofing and a Gore-Tex jacket with Thinsulate will provide all three of these things. Of course you can get your jacket with down filling which by weight is warmer than synthetic fibers however it is pretty pricey and takes a long time to dry should it get wet. If your temperatures aren’t too extreme however, a Gore-Tex shell will be fine with proper under layers.

When it comes to gloves vs. mittens, there are a couple of pros and cons. Mittens are warmer as your fingers are allowed to share radiant heat but they don’t make it so easy when it comes time to pull a trigger. There are combination mitten/gloves where only half the fingers are gloved and the “mitt” can be pulled over the top when the fingers are not needed but this debate can also be solved by just simply using a muff. You can also throw a couple of hand warmers in a muff that will keep your hands toasty until its time to use them.

And finally head wear. I love my ball caps but two things I WILL ALWAYS have in my pack is a good fleece beanie and fleece face mask that covers both my head AND neck.

We all know how tempting it is to come out of the field when we get cold, wet and miserable. Visions of hot coffee and warm food begin taking the place of giant racks. We might be able to make memories back at camp but we can’t fill tags or freezers that way so if you will stick to this basic system, you should be able to spend more time in the field this season and less time indoors.