Well, for those of us in the northern parts of the country, we’re in the midst of the coldest time of the year. Especially up here in the mountains of northern New Hampshire, where, with the exception of a couple of isolated “nice” days (when the mercury crept up as high as 40ºF for a day), it’s been in the low to negative digits for several weeks now.
During the winter, most folks choose to spend almost all of their time indoors. But for the rest of us nuts, who choose to spend time in the outdoors in the cold of winter, (or those who are required to work outdoors) we face some very specific challenges and very real dangers.
Unlike in hot, human condition, the human body can do very little to adapt to a cold environment. Wind chill, wetness, heat loss through exposure and insufficient heat generation are all factors making it difficult to maintain a safe core temperature above 94ºF.
There are two critical factors involved in surviving in a cold environment. The first is generating heat through aerobic activity. Hypothermia can set in FAST and if you’re at rest in a cold environment a large amount of body heat is lost through convection (heat radiating out and away from your body). It is critical to keep your body generating heat through aerobic activity, while careful not to overheat.
Which brings us to our second factor: clothing. It can be compelling to overdress for a winter excursion outdoors, but vigorous activity, such as hiking can significantly raise your core temperature if the heat is not properly dissipated. Excessive overheating due to lack of thermoregulation will lead to profuse sweating, and rapid heat loss. In a winter survival situation, your problems get worse as your garments trap all that perspiration and become wet, further dropping in temperature.
It is important to know not only what to wear to survive outdoors in the cold, but also how much to wear and how to regulate the heat your body generates.
There are many different kinds of cold weather equipment and clothing. But don’t feel like you have run out and buy the newest, most expensive gear. Older gear will keep you warm as long as you apply a few cold weather principles. If you can afford the newer types of clothing that are available, then by all means use them. If not, then your clothing should be entirely wool, with the possible exception of a windbreaker.
Not only do you need to have enough climate-appropriate clothing to protect you from the cold, you also have to know how to maximize the warmth you get from it. For example, you should always keep your head covered. You will lose a large percentage of your body heat from an unprotected head. Furthermore, the brain is highly susceptible to cold and can stand the least amount of cooling. Because there is so much blood circulation in the head, most of which is on the surface, you can lose heat quickly if you do not cover your head.
Other areas of your body that you should keep protected are the neck, wrists, and ankles. These areas of the body have very little insulating fat, which make them good radiators of heat.
There are four basic keys to keep in mind in order to stay warm. An easy way to remember these basic principles is to use the word COLD as a mnemonic device :
- C – Keep Your Clothing Clean
This principle is important in any climate for sanitation and comfort, but in winter, it is also important from the standpoint of warmth. Clothes matted with dirt and grease lose much of their insulation value. Heat can escape more easily from the body through the clothing’s crushed or filled up air pockets.
When your body is too hot, you sweat and your clothing absorbs the moisture. This reduces your warmth in two ways: damp clothing is not an effective insulator, and as your sweat evaporates, it cools your body. You should always avoid sweating. If you feel yourself getting too hot, and starting to perspire, adjust your clothing so that you do not sweat. You can do this by partially opening your coat, or parka, or by removing an inner layer of clothing. You can also remove gloves, or mittens, or throw back your hood (if you’re wearing one) or switch to a lighter hat. The head and hands will efficiently dissipate excess body heat.
- L – Wear Clothes in Loose Layers
Wearing clothes in loose-fitting layers will create air pockets that trap body heat, increasing its insulating value. Tight fitting clothing and boots restrict blood circulation and invite cold injury. Several layers of lightweight clothing are better than one equally thick layer of clothing, due to the dead-air space between layers. Also, you can remove or add clothing layers to regulate your body temperature, preventing excessive sweating or to increase warmth.
This may seem like an obvious concern, but in cold temperatures, your inner layers of clothing can become wet from sweat and your outer layer, if not water repellent, can become wet from snow and frost melted by body heat. Whenever possible, wear water repellent outer clothing. It will shed most of the water collected from melting snow and frost. Before entering a heated shelter, brush off snow and frost. Despite the precautions you take, there will be times when you cannot keep from getting wet. At such times, drying your clothing may become a major problem. You can hang your damp mittens/gloves and socks outside your shelter during the day to dry. In freezing temperatures, the wind and sun will sometimes dry this clothing. You can also place damp socks or mittens, unfolded, near your body so that your body heat can dry them. In a campsite, hang damp clothing inside the shelter near the top, using drying lines or improvised racks. You may even be able to dry each item by holding it before an open fire. Dry leather items slowly. If no other means are available for drying your boots, put them between your sleeping bag shell and liner. Your body heat will help to dry the leather.
To read more about staying safe and surviving out in the cold CLICK HERE.