November 04, 2010
Your cold-weather hunting success can rise only as high as your cold-weather comfort.
STRAPPING MYSELF INTO the treestand, I had a hunch a weather change was afoot, and I was not wrong. The change was instantaneous and severe as a light breeze flared into 40-mph-plus gusts, a cloudy sky erupted into bursts of sleet, and the temperature hurtled downward like a bungee jumper on a broken cord.
Frantically I dug to the bottom of my daypack for my stowed raingear, and with the pants on and the jacket zipped snugly, I felt much calmer in the chaos of wind-whipped branches and pelting ice pellets. Prior to the sweeping front, whitetails were beginning to make their way to an adjacent field, but the weather stopped the action cold. Time was against me in every way, as shooting light was diminishing, and my body was beginning to submit to the conditions.
Would I even be able to make the shot if a buck came within range? After all, aiming at a buck is tough enough under the effects of buck fever, and adding the shakes from cold weather only aggravates the problem. I'll reveal the outcome of that bitter weather hunt in a moment, but first let me share some of the knowledge I've gained from hunting and guiding for whitetails during late fall and winter in the Dakotas, Wyoming, Montana, and other northern states.
THE PHYSIOLOGY OF COLD
As a warm-blooded critter, you must maintain a constant body temperature, and you do this by generating body heat in cold temperatures and cooling yourself in hot. You can study up for yourself on the cooling process for your next jungle hunt, but for now, let's focus on staying warm on winter hunts. To do that, you must understand the major processes that make you cold.
No. 1 is radiation, the transfer of energy between two elements of different temperatures. Your body maintains a constant temperature of about 98 degrees, but in cold weather your skin radiates heat to the outside, colder environment. To prevent that, you must insulate your body to trap heat against your skin.
Even in the face of wind, sleet, and plummeting temperatures, I stayed comfortable on stand long enough to wait out this big guy.
No. 2 is evaporation. In warm weather, sweat is good, because the evaporation of moisture (sweat) requires the use of energy, which cools the surface of your skin. The same thing happens in cold weather, but the effects are bad -- evaporation chills you. The solutions are to regulate activity to prevent sweating and to wear clothing that wicks moisture away from the skin.
No. 3 is respiration. During the normal process of breathing, you dispel moisture from your body. The colder and drier the air, and the heavier your breathing, the greater the heat loss. This is the least preventable form of heat loss, but you can regulate it to some extent by moderating physical activity to avoid inhaling huge quantities of cold air.
No. 4 is convection, the transfer of heat as two objects meet, one or both of which may be moving. The chief demon here is wind chill. As cold, moving air hits your warm skin, it sweeps heat from your body. To compound the effects, your body reacts by drawing blood away from the extremities to protect vital organs, which can lead to frostbite in the hands and feet. Prevent this by wearing garments that block the wind.
No. 5 is conduction, the transfer of heat between two immobile objects. This occurs when you plant your warm buns on a cold treestand seat, lean against the damp trunk of a tree, or take up a ground ambush and use an icy rock for a stool. The solution here is to insulate yourself from cold objects.
If any of these factors become uncontrollable, you could face shivering and ultimately hypothermia, a life-threatening condition that occurs when the body loses more heat than it can generate.
Brad bagged this 190+ brute during the 2008 season.
Using second-rate clothing led to the demise of many of my hunts in my early years. Some of my garments were inefficient in insulating and repelling moisture -- and noisy, too. One of the best whitetails I ever decoyed was lucky I was wearing garage-sale clothing. As I rattled antlers right after sunrise, the temperature was in the teens and the air was crisper than oil-fried potato chips. Within minutes, three separate bucks converged on the doe decoy below my stand.
As a mature, heavy-antlered 4x5 buck sauntered up to the decoy, I raised my bow and moved slightly to line up for the shot. Underneath my cotton snow camouflage, I wore an old snowmobile suit for insulation. When the suit crinkled like a cold plastic tarp, the bucks bolted, leaving me and my decoy staring dumbly at each other.
You probably already understand the concept of layering, but it's what you layer with that can extend your time afield. The layering system comprises three building blocks: base layer, insulation, and protective layer.
The base layer against your skin from head to toe insulates (the level of insulation depends on the thickness of the garment) and, perhaps more importantly, wicks moisture away from your skin. To best accomplish these chores, wear lightweight, polyester-based materials, such as Under Armour's ColdGear. UA's Metal ColdGear transports moisture away from the skin and insulates through added fleece.
Regardless of the base-layer brand you choose, insist on polyester construction, not cotton. Cotton retains moisture and dries slowly -- freezing you all the while. Some folks prefer wool as their base layer, especially the Merino wool version that doesn't itch -- at least not as much as regular wool. Wool works, but it doesn't transport moisture as well as polyester, and, thus, it gets heavy. Personally, I prefer poly.
Add an insulating layer over the base layer. The mainstay for insulation for decades has been down, and I've shot many whitetails while wearing my grandfather's hand-me-down down vest. On one particular hunt, the temperature at dawn was in the single digits. I had been in the stand for more than an hour, and the down vest definitely gave me an edge in staying warm as the buck took his time making his way to my stand. Although I was quaking from adrenalin, my core temperature was stable when the buck stopped 15 yards away, giving me a quartering-away shot.
After confirming the buck's demise, I rushed to town to get a frame pack to retrieve the buck, and then I grabbed my young son to join in on the celebration. Just as we started the chore, snowflakes started falling. I pulled the down vest out of my pack and wrapped my son in it, and we both stayed warm while finishing the job at hand. Yeah, down still works.
From time to time I still use that old vest, but today I prefer modern insulations. Down collapses and becomes useless when wet, and it dries very slowly. Synthetic fleece shirts and jackets are unbeatable as initial insulation layers. Polyester fabrics with a velour finish, such as Artic Fleece and Polartec Classic, trap body heat, weigh next to nothing, and dry quickly. Available in 100, 200, and 300 weights, Polartec Classic fleece offers versatility to match all conditions.
On truly bitter days, add a heavier insulating layer. Synthetic insulations like Thinsulate Supreme, Primaloft, Microloft, and Polarguard, which trap air between fiber strands, make excellent jackets and pants for maximum warmth. Again, these synthetic materials are warm, lightweight, water resistant, and quick-drying.
Tony Zambon used his longbow to down this 193-incher.
Finally, wrap the entire ensemble in a waterproof-yet-breathable outer layer. This shell not only protects your insulation and base layer from outside moisture but also blocks the wind to reduce wind chill. You may not always need this additional layer, but always carry lightweight raingear for protection against rain, snow, and wind. Gore-Tex is the granddaddy of waterproof/breathable fabrics, but Under Armour's ArmourStealth, Cabela's Dry-Plus, and other products perform similarly.
Perhaps most importantly, apply this sensible layering system to your extremities. The neck and head are major sources of heat loss, so protect these areas at all costs. In mild weather, lightweight head protection like Sitka Gear's Traverse Beanie and a ball cap might be adequate, but in colder weather, add a fleece or wool sock hat (a tuque in Canada) or balaclava, and complete the system with a hood and scarf for full neck/head protection.
Protect your feet, starting with a base layer of lightweight poly socks, adding insulation with heavier wool or blended materials made with Primaloft or other synthetics, and topping off the system with insulated pac boots. Add chemical toe warmers for ultimate warmth.
On your hands, wear snug poly gloves, and add waterproof gloves or heavy mittens as needed. On really cold days, nothing beats an insulated hand muff like the ICEBREAKER HanBlanket for ensuring warm hands. You can get by with wearing lightweight gloves inside the muff.
For maximum warmth, insert a couple of HeatMax or similar chemical body warmers (body warmers produce more heat and last longer than the smaller hand warmers). ThermalLine and other companies make specialized clothing to hold chemical warmers in strategic areas such as the kidneys, neck, head, and feet. If I find myself needing heat in a specific area without a strategic pocket, I duct-tape warmers in place. Regardless of how you secure heat packets, take care not to suffocate them. They must have air to produce heat.
For ultimate protection on the most intolerable days, top off your layering system with a body bag such as the Heater Body Suit. While providing the warmth of a sleeping bag, this garment is designed for mobility and silence to ensure hunting stealth.
MUNCH AWAY YOUR SHIVERS
Never overlook the importance of food for cold-weather warmth. Depending on your height and weight, your body requires between 2,000 and 2,500 calories per day for basic metabolism. Then, according to research by the U.S. Army Research Institute of Environmental Medicine, it needs at least 10 to 40 percent more calories per day to stay warm in cold weather. That means you must consume roughly 4,500 calories per day to stay warm in cold weather. Of course, the exact number depends on your size, your level of activity, and the weather conditions.
Regardless of the exact caloric intake, keep these ratios in mind for a winter diet: Carbohydrates should comprise about 60 percent of your diet. Pastas, whole-grain breads, cereals, and potatoes fit into this category. Carbs convert most quickly to energy for heat and added zip. Fats should make up 25 to 30 percent of your daily caloric intake. They take longer to convert than carbs, but they produce twice the punch. Nuts, butter, margarine, and cheese give you an ample ratio of fats. Finally, round out your diet with about 15 percent protein. Rather than downing a huge steak, look at peanuts, legumes, milk, or meaty sandwiches as a combo. Drown this menu with lots of water to stay hydrated.
The vicious front I experienced earlier finally settled, and as quickly as the deer disappeared, they busily began moving toward the feeding fields again. Despite an icy downpour and ample gusts to launch wind chill, I was surprisingly warm in my Under Armour fleece and raingear. A buck skirting the perimeter of my stand was no match for my soft grunts, and he swung my way as if directed by an aircraft carrier flight crew.
At 12 yards the buck hit a wall of scent I had placed before the storm, and as he immersed himself in the aroma therapy, I drew my bow and settled my one-pin sight on his vitals. As I watched the buck teeter seconds later, a wave of warmth erased the reality of a chilly evening.
The author is a well-known outdoor writer and photographer from Sheridan, Wyoming.