Heat on the Go
So what can we do to provide heat when we have to move from place to place such as during a bug out? Let’s assume for a minute that you are not moving in a car or vehicle with a working heater (which conveniently recovers heat from combustion and vents it into the driver and passenger compartments).
Use the acronym COLD to plan for wear of winter weather clothing:
Loose and in Layers
Clean: clean clothing retains its insulating properties better than dirty clothing. Dirt gets in the pores and empty spaces of clothing and permits more heat to radiate out. This is especially important for undergarments and socks which can get dirty fast.
Loose and in Layers: While you are outside and fairly inactive – you should dress appropriately for the weather. Loose and in layers was always our guidance in cold weather training. Three layers is a standard plan – the base, a mid layer, and the outer layer. The base traps your body heat close to your skin but ideally wicks moisture away so that this layer stays dry. A set of poly pro form fitting under shirt and long johns should be your first layer.
The mid layer provides insulation to further trap heat. Many people use a fleece. Wool is a good insulator as it doesn’t lose its insulating qualities if it gets wet or damp. Avoid cotton which is the exact opposite of wool and doesn’t work well retaining heat when wet.
The outer layer is for protection from the environment, a wind proof and / or water resistant material that prevents heat loss. Overalls and a parka with a hood are ideal for this layer. The water-resistant shell can be worn if the weather is wet but not so cold. There are plenty of good winter parkas with a removable liner.
All clothing is loose but not too loose – you don’t want a lot of air exchange between layers as you move as you will then just have to heat up that new volume of air.
Remember that your shoes or boots should also permit comfortable wear of thick socks, if the fit is too snug it will constrict blood flow and potentially increase risk of a cold weather injury.
There are many synthetic materials on the market that are great for keeping warm outdoors but be aware that many of them will melt if exposed to fire. Keep this in mind when you stop for the night – have at least one layer of wool that you can use around the campfire. If you ruin your synthetic gloves or jacket – it has zero usefulness the next day.
Avoid Overheating: If you get active (moving on foot to the next location carrying your bug out bag), you need to start stripping down layers to avoid overheating. You may take off your outer layer completely and unzip your mid layer to increase air flow and vent off body heat.
Dry: likewise, if you are starting to sweat, shed a layer or unzip / open up a layer. If you have finished a long hike or other exerting activity and you are even a little damp and there is no fire or shelter, it is best to strip down and change your clothes. I would even recommend stripping all the way down (as long as conditions are not so windy as to risk frost bite from wind chill) to get in dry undergarments. Just a little dampness can leave you feeling chilled while getting dry, clean clothes can quickly warm you back up.
Extremities: You lose a lot of heat through your head, hands and feet (if you are daring, you can try shaving your head in the winter and see how much colder things seem). Since the head protects the brain you don’t want your brain housing group to chill down as it will lead to diminished decision making. A good watch cap should do the trick and then add your parka hood to provide further protection. A nice set of gloves with a liner can protect your hands – even the old military leather shell and wool liners were pretty warm. In really cold climates, mittens do better as the fingers are not isolated. A good set of insulated boots is a must in cold weather but you don’t want your feet to sweat. If they do, change your socks as soon as practical. Vapor barrier boots are a bit clumsy but provide great insulation.
Having grown up in Minnesota, I have seen some cold winters. Keeping your neck warm really helps keep your body warm. I prefer a dickie over a neck gaitor as it covers the front of your neck better. I also used to use a neoprene face mask to avoid exposure of my face to freezing winds. The neoprene traps moisture in the layer and heats it up kind of like a SCUBA diver’s wetsuit. This is the only exception I would make to the Dry rule.
Keeping warm while stationary
In the 18th and 19th centuries when people moved in animal drawn coaches or wagons, they had some ingenious methods to keep them warm without the benefit of waste heat from a combustion engine. See if you can get some old bed warmers or foot stoves. These are basically boxes (wood frame around a metal pan or bottles that you place coals, heated stones, or hot water inside. Insulate the bottom and sides and let the heat escape through the top. Heat them up while cooking or during the evening next to or on top of the wood stove and then place them under your seat in the vehicle or bed at night.
I want to recommend you look at Ed Veisturs “No Shortcuts to the Top”: It has a great chapter on the mechanics of living on the mountain during a climb. From wear of gear to how to take a crap in the cold. Excellent read.
The power of science (ok, of chemistry)
What about those chemical hand and foot warmers? You can actually re-use some of them by boiling them and then cooling them down slowly. Or you can make your own. Hand warmers are basically a super-cooled mixture of sodium acetate. When activated, the mixture hardens and releases heat. The recipe is simple: stir in one tablespoon of baking soda per cup of vinegar and boil off about half the volume. Beware – probably best to do this outside as it is pretty stinky. You end up with a yellowish liquid (the sodium acetate) and some crystals. Pour the liquid off and store and then scrape the crystals into a bag. Adding a crystal to the liquid will initiate the process. You just have to boil the mixture again to re-use. The detailed recipe is available from Popular Science at http://www.popsci.com/article/diy/conquer-cold-diy-hand-warmers. And it even explains how to fabricate vinyl packaging for the hand warmer. Who said science is not cool? In this case, they are literally right and figuratively wrong.
Keep on prepping.
De Oppresso Liber