December 23, 2022
On Nov. 11, 2019, the whitetail rut was in full swing, and I still had an Illinois buck tag burning a hole in my pocket. I hiked into a doe bedding area around noon, and by sunset I was battling for visibility, as an unexpected and unusual cold front pushed into the area. Here in the southeastern part of the state, we almost never see measurable snow during the rut, let alone near-zero windchill temperatures. And I’ll be the first to admit, I was not prepared for that weather event.
A borderline blizzard during the rut seemed like such an unlikely occurrence that I didn’t take precautions with my gear, making the hunt less than comfortable; but I survived. November 12th is one of my favorite days to sit all day and hunt for a mature buck, but the forecast for the following day was to be even more challenging: 12 degrees at daybreak with 15-20 mph winds, and it called for more snow on the ground than I’ve ever seen for the date on the calendar.
It was going to be a difficult task, but if I was going to pull off a lengthy sit, I needed to break out some serious cold weather gear and approach the day like a late-winter hunt.
The Science of Thermoregulation
The human body prefers to always maintain a core temperature between 98 °F and 99.5 °F through a process called thermoregulation. And it is governed by the hypothalamus in our brain. When our core body temperature falls below the ideal range, the hypothalamus acts like a little thermostat. When cold, the gland initiates cold weather protocol.
Blood vessels to our hands and feet constrict to keep blood in our core and reduce the heat loss from our extremities, leading to numbness and tingling in our digits and toes. The gland makes us shiver to force muscles to release heat to raise our core temperature. The thyroid gland gets involved, stimulating body cells to increase metabolic heat production. The feedback loop between the hypothalamus core body temperature is always in motion, and understanding this is key for staying warm.
The Science of Heat Exchange
A key concept in thermodynamics of the human body is quite a simple one: heat always flows from a higher concentration to a lower concentration. With this fundamental in place, there are four basic principles of heat exchange to consider when gearing up for a cold weather whitetail hunt. Let us examine each in detail, and how they factor into staying warm in the field.
Radiation:Radiation is the transfer of heat via infrared waves, and this is how the majority of our body heat is lost while hunting in cold temperatures. Our bodies release heat into the environment we are sitting in like one of those woodburning, potbellied stoves. To put it simply, our bodies slowly release heat into the colder surroundings passively, and this is the single greatest obstacle for stand longevity in cold conditions. Around 60 percent of body heat loss is through radiation.
Conduction:Have you ever noticed just how cold your feet and rump can get when in contact with metal tree stands in sub-freezing weather? Ever notice how painfully numb your bare hands can get gripping your bow, using binoculars or climbing up metal tree steps when it’s bone-chilling cold? The principle of conduction is to blame here. Conduction is simply the transfer of heat between two objects that are in direct contact with one another.
Convection:Convection is the transfer of body heat into the air surrounding the skin, and this phenomenon occurs mainly due to the wind our body faces while in the field. Cold wind sucks the heat from the body, and convection heat loss worsens as wind speed increases and ambient temperature decreases, also known as “wind chill.” Sitting a field edge stand in single-digit temperatures with 15-20 mph wind speeds means convection will play a factor into my longevity in the tree. And I’ll have to dress accordingly.
EvaporationHave you ever hiked to your stand with all your winter clothing on, only to be freezing cold after the first hour in the tree? If you’re like me, you can work up quite a sweat — even in the coldest of conditions. When that happens, evaporation can drop your core temperature in a hurry, making you uncomfortable even if you have the best cold weather outerwear or boots. In cold conditions, every effort needs to be made to remain dry and prevent heat loss. Sweat is the enemy on winter hunts.
Combating Heat Loss
With an understanding of the basic principles that zap our body temperature on cold weather hunts, there are many essential items that a hunter can choose to help defend against heat loss.
With respect to radiation heat loss, insulating in layers is a critical concept. Much like keeping heat in a home, with proper layers of insulation, heat remains inside the human body. When I find myself on stand, I will usually have a layer of First Lite merino wool base layers next to my skin. I like to then add a vintage wool Commando Sweater from L.L. Bean as my mid-layer top. My outer layer goes over the top of this combo, and I have had great success using Sitka’s Fanatic series bibs and jacket to keep out the cold.
The final pieces of outerwear to help stop radiative heat loss focus on my head. I like to pair a heavy-duty, windproof neck gaiter with a windproof stocking cap, and I’ll sometimes pack two of each to layer for long days in frigid weather. It may look a little funny, but two hats and two layered neck gaiters have been my favorite way to fight off the cold in recent years.
When it comes to defending against convection heat loss, the whitetail hunter needs to guard against the wind. Several layers of clothing won’t matter if the outer layer isn’t somewhat wind resistant. One of my favorite windproof pieces of gear is a wind and waterproof shell made by Rivers West. It is virtually impenetrable to air flow. Sitka’s Stratus series is also great for shucking the wind, and I’ve had great results with their Stratus Vest as a layering piece.
Regarding footwear of choice for beating the cold weather, a quality pac boot like the Kenetrek Northern deserves a mention. I, and many other whitetail hunters, have been conditioned to believe that rubber boots are superior at eliminating ground scent. While I agree this may be true, all rubber boots get cold.
A pac boot in below-freezing conditions is a game-changing piece of gear for one reason: if my feet get painful from the cold, my mind is on my feet and not on the hunt. If my feet are comfortable, my mind is on task, and I feel I am a more formidable winter hunter. Add an Icebreaker’s set of boot blankets over the top and a pair of Smartwool socks on my feet, and I can sit dark to dark in stiff winter weather chasing after a mature buck.
Conduction heat loss can be easily prevented on a winter hunt for a big buck. A hunter needs to protect three extremities. As mentioned above, proper footwear helps insulate the feet from the icy, metal tree stand. Hands are also on this list. When bowhunting, I like the dexterity found in wool, fingerless gloves; and I’ll sometimes add a thin liner glove underneath.
In snowy, wet or windy conditions, a windproof, insulated, Goretx glove is in order to protect digits from freezing as they grab metal climbing sticks or the handle of a bow. I like to pack both types of gloves with me.
A final area for defense against conduction heat loss is your rump. In arctic weather, I will pack in a Hunt Comfort gel seat cushion to keep the metal tree stand from robbing the heat from my backside. This aids in staying comfortable and focused while on watch for a giant buck.
I find the principle of evaporation heat loss to be a tricky subject to contain. In order to prevent cold weather evaporation, the late season whitetail hunter needs to stay dry. Obviously, wearing waterproof boots, gloves and outer layers is a must in wet weather, but this comes at the cost of breathability of the garments. If I put on all my windproof and waterproof layers and hike to my tree stand, I am usually pouring sweat by the time I arrive. Thus, the way to beat evaporative heat loss isn’t just to stay dry, it’s to not sweat yourself cold.
This is easier said than done, but what I have taken to in recent years is what my boy and I call “the polar bear club.” He and I like to strap our outerwear and mid-layers onto our pack systems using gear ties or ratchet ropes. We leave the truck in our boots, gloves, base layer bottoms and a wicking t-shirt up top and hike to our tree stand setup. Once there, I’ll rest a bit and let the cold weather help work in my favor to keep me from overheating. If I have sweat through the t-shirt, I pull it off and take a breather before adding my layers. After a rest, I dress at the tree, climb up, and if I have done my part, I’ve stayed sweat free.
Sweaty feet are a huge reason why toes get cold during a long, cold sit in the winter woods; but there are a few remedies one can try. If I must cross water and rubber boots must be used, I know my staying power below freezing will be affected. To combat sweating in rubber boots, I actually use Mitchum gel antiperspirant on my feet. I rub it in like lotion and allow the goop to dry before I put a liner sock on for the hike in. I find this helps cut my foot sweat by a huge margin.
Once settled in the tree and I can feel my body temperature normalizing, I’ll reach into my pack for a dry pair of wool socks and change socks on stand. All this sounds like a pain, and it is. But all these tricks can certainly help you maintain comfort from heat loss when competing with winter weather to burn a buck tag.
I’ll never forget the hunt I had here in Illinois on Nov. 12th, 2019. We never have a winter storm this early in the fall where I live. Never. It felt strange digging out all my winter weather gear on historically one of the best days of the whitetail rut, but I wasn’t going to miss it for the world.
With the windchill touching 7 degrees F, I hunted on the downwind side of a doe bedding area I had taken a liking to. I hiked in mid-morning when I hoped all the deer were on their bellies, bedded down in the snow. I packed most of my clothes in, took care of my hands and feet and paid attention to my speed, trying not to sweat. The windchill and snowfall were so unique for the date on the calendar, that I knew I would have a wild-west style hunt. And I most certainly did.
The air was frigid, and wet snow clung to everything, making for cold fingers and slow hiking. It was a tough hunt, but with the right gear, I made it to dark and felt very happy with the effort and the number of rutting bucks I saw. Given this was likely a once-in-a-lifetime cold front, those bucks didn’t seem to pay any mind!