Cold Weather Camping Information
Cold-Weather Camping
12/1/13
Much of this information comes from the Boy Scout book: Okpik: Cold-Weather Camping available on Amazon here:
You will need at least the following things to stay comfortable on a winter campout:
1. A good mental attitude.
2. Plenty of food and water.
3. Dry clothing.
4. Adequate Sleep.
Homeostasis:
Your body is a furnace. Its fuels are food, water, and oxygen. It works best when it is regularly fed, rested, and kept at a steady temperature of 98.6 F. This is regulated through a process known as homeostasis.
The homeostatic process works like your body’s thermostat, using your arms and legs to radiate heat away from your torso, like a car’s radiator. When your body is producing too much heat for your vital organs, the homeostatic process dilates the blood vessels in your arms, legs, hands, and feet to allow full blood flow to the skin surfaces of your extremities.
When your body is not producing enough heat to keep your vital organs warm enough, your blood vessels constrict, keeping more of the heat in your torso. Blood flow to the fingers and toes can be cut back as much as 99 percent. This is why your fingers and toes get cold, numb, and are susceptible to frostbite. When your fingers get cold, it is much harder to do things, and everything takes longer.
Since your brain needs oxygen to function, your body can’t cut off the blood flow to your head to conserve heat. This is why it is very important to keep your head covered in cold weather.
Types of heat loss:
Radiation: Your head is the most efficient part of your body’s radiator system. An unprotected head will lose up to one-half of your body’s total heat production at 40 F, and ¾ of total body heat production at 5 F. Remember, “When your feet are cold, put on your hat.”
Conduction: You will lose heat this way if you carry metal tools, sit on a rock, lay in the snow, etc. Water can conduct 30 times more heat than air. This means that wet clothing can suck heat from your body much faster than clean, dry clothing. Dry clothing is 240 times better at keeping you warm than is wet clothing. (p57)
Convection: When your body radiates heat, it warms a thin layer of air around your body. This air is almost as warm as your skin. If this warm air layer is kept close to your body, you will remain warm. If there is a breeze, this air is blown away. This is losing heat through convection. If you trap dead air between layers of clothing, this will reduce convection heat loss, and will keep you warmer.
Evaporation: As perspiration evaporates from your skin, you lose heat. If you are wearing waterproof clothing, and the water vapor can’t escape, it will condense and freeze. Soon, you will be wearing a suit of ice armor.
Respiration: You also lose heat by inhaling cool air and exhaling warm air. There is little you can do to minimize this.
Amounts of heat loss:
Radiation: 55%
Evaporation: 21%
Conduction and Convection: 15%
Respiration: 9%
Secrets of Keeping Warm
Keep your core warm. Keep your activity rate and clothing appropriate for the weather conditions.
Make sure your blood can circulate freely. Tight clothes or tight boots will constrict blood flow, and make you cold.
Wear the right type and amount of clothing. Regulate your clothing according to your activity rate. This is your most effective way to stay comfortable.
Pay attention to internal signals. Don’t wait until you are sweating to remove a layer. Don’t wait until you are shivering to add a layer.
Insulation
Natural fibers (like cotton, wool, linen, and silk) are proteins. They are hydrophiles, meaning they absorb water into their cell structure. Cotton absorbs a lot of water. Because of this, we have the sayings “Cotton kills” and “Cotton is rotten”. Because wool absorbs less water than cotton, we have the saying that “wool is warm, even when wet.” This may be true, but remember that nothing is warm when it is frozen!
Synthetic fibers are hydrophobic. They won’t absorb water into their fibers. Polypropylene, for example, will absorb less than 1% of its weight in moisture. Synthetics are easier to dry since they hold water only on the surface of the fiber, not in the cell structure.
This is important because you sweat a lot. Your body loses one-and-a-half pints of water each day from insensible perspiration. This is not visible, and exists just to keep your skin flexible. If you add to this perceptible perspiration from exertion, your clothes will have to wick away a lot of water. Don’t wear something that will hold the water. You will get cold.
Remember the Acronym to keeping warm: C.O.L.D.
Keep Clean
Avoid Overheating
Wear Layers
Stay Dry
You will need clothing that protects you from cold and holds your body heat. The layers should be thin so frost forms between layers, not inside the insulation. Your clothing will need to be warm, not stylish. Again, the best method for insulating is layering. Several medium-weight layers provide more insulation and flexibility than one heavy garment. This is true even if the heavy garment is thicker than the combined thinner layers because the dead air trapped between thinner layers insulates.
If you are dressed appropriately to be well insulated against the cold, a fire will not keep you warm. The insulation that keeps out the cold also keeps out the heat. If you need a fire to keep you warm, you aren’t wearing the right clothes.
Types of Cold:
Wet cold: 14 F to 50 F. If temperatures are above freezing during the day and below freezing during the night, you are much more likely to get wet, and get hypothermia. Wet cold is also often accompanied by rain or wet snow that causes the ground to become muddy or slushy. Be sure to carry rain gear and extra dry clothing.
Dry cold: -20F to 14F. Snow is dry and in the form of small crystals. Strong winds can cause temperatures to seem colder. Dry-cold clothing is the same as for wet-cold conditions except that more insulating layers are needed, and the rain-protection for wet cold can be replaced by windproof clothing.
Arctic Cold: below -20F.
Cold Weather Sleeping:
Sleeping is one of the factors that can make or break a cold-weather campout. Your body cools down during sleep. The blood is drawn from the extremities and brought to the core of your body.
The ground is colder than your body. You MUST have proper insulation to prevent heat loss by conduction. Put layers UNDER you.
Remember C.O.L.D. to stay warm with bedding, just like with clothing.
Keep your bedding CLEAN.
To keep from OVERHEATING, your bedding must be ventilated. Overheating in a sleeping bag produces perspiration just like when you wear too much clothing.
Your bedding should be LAYERED. This makes it easier to remove the frost buildup that occurs naturally when your body produces warmth. This is a major concern if you are camping more than one night.
Keep your equipment DRY by pumping all of the warm, moist air out of your sleeping bag in the morning and airing and exposing it to the radiant warmth of the sun. Turn the bag inside out and check for frost. Leave it open until it cools to air temperature.
Nutrition
Cold stimulates a ravenous appetite. Because of this, each person should always carry a snack of trail-mix in his pocket.
Grub masters, plan on each person’s eating 4000 calories per day. You will need more fats and more proteins in cold weather than in warm weather. Plan on:
40% of your calories from Carbohydrates (primarily complex carbohydrates)
40% from Fats
20% from Proteins
This should be consumed with 2.5 to 3 quarts of water per day.
Try to minimize eating or drinking anything that is much hotter or much colder than your body temperature. If your food is too hot, it will cause you to sweat. If too cold, your body has to warm your food.
Breakfast can be hot cereals, either cooked or instant. Wheat germ can be added to increase nutrient value. The fat for breakfast comes mainly from butter or margarine added to hot cereal. Corn oil margarine is a good choice. Dry fruit can be eaten, or added to cereal.
Lunch should be prepared ahead, or require little or no preparation. Something like hard, fortified crackers or Hudson Bay Bread (see my recipe below), spread with peanut butter, honey, or jelly are a good option. A good lunch will also include a fruit drink or dried fruit, and a trail type snack.
Dinner should provide the highest amount of protein of the day. This provides warmth and promotes tissue repair during your sleep. You should plan a one pot hot main dish including a starch, a sauce, vegetables, and a meat. Dessert can be one that requires preparation and cooling, such as pudding, cheesecakes, and gelatin desserts. The main dish can be prepared at home, spread in a shallow pan, and frozen. To use the frozen dish at camp, break the frozen food into smaller pieces and add it to hot water.
The bedtime snack should be a high calorie combination of carbohydrates and proteins. Something like a Snickers bar or Hudson Bay Bread are great choices.
Hudson Bay Bread Recipe (my personal adaptation)
Preheat oven to 325F.
Mix the following:
2 sticks butter (melted)
2 cups peanut butter
2 cups of sugar
1 cup maple syrup
1 cup corn syrup
1 package chocolate chips
9 cups instant rolled oats
Spread into two cookie sheets with a rolling pin. Bake at 325 for 18 minutes.
Cut while still hot. Remove from pan before cooling completely.