The most overlooked piece of gear for survival or bushcraft is the blanket. There are so many resources devoted to knives and hatchets, but while the blanket may not be as sexy of a topic, it has so many uses for one wandering the wilderness that it should be a carefully chosen tool for your pack

One of the first things to learn is that blankets, no matter how good, are not “warm,” they don’t generate heat. Wrap a jar of water in the warmest, thickest, softest woolen blanket you can find and place it out of doors over night in a zero temperature and see what you have in the morning. No, there is no warmth coming from the blankets, but the warmth comes from the human body and the purpose of the blanket is to retain this warmth, to prevent its escape. It must therefore be a non-conductor of heat. And remember that there is no such thing as cold, for what we call cold is merely an absence of heat, and we call it cold for convenience.

Suppose you are sleeping, or attempting to sleep out of doors on a night so cold that the trees pop like pistols. You are wrapped in a pair of woolen blankets and it is only this wrapping that is between you and the frosty, chilling air. But inside of those blankets your body is giving out heat waves, the air on the inside becomes warm, and you are comfortable. Suppose again that the blankets are not the right kind, they will not retain heat, and as a consequence you become cold. You sit up, replenish the fire and swear to yourself, but you don’t know why you can’t keep warm. You say the cold gets through your blankets and you firmly believe this. As a matter of fact it is the heat that gets through, not the cold.

Go Wool or Go Home

Outside of fur the best heat-retaining material used for blankets is pure wool. A little cotton may do no noticeable harm, if properly used in conjunction with the wool, but it certainly does no good, and it really decreases the warmth of the blanket in direct proportion to the quantity used, therefore I say the best blankets are made of pure wool.

Now it is not difficult to get together a quantity of blankets that will keep you warm on the coldest night, but the trouble will come when you want to transport them. Which we all know, when in the woods, the weight of your gear is crucial.  I have slept out on nights when it would have required a half-dozen or more of the heaviest woolen blankets made to keep me near-comfortable, however carrying them would be impossible.

There are two choices to remedy this problem. Either you will not be comfortable in the woods during zero weather unless you have a way of transporting your camp duffle other than by back-packing, or you must find a lighter, warmer blanket than can be made of wool. The latter is the solution.

Woolen blankets are good, in fact the best thing made, for camping in spring, summer and fall. As long as the temperatures do not go lower than 10 or 20 degrees above zero and a fire may be kept burning all night a pair of blankets are hard to beat. But when the temperature falls lower the shivering spells preceding each “fire-fixing” become too frequent and the cat-naps too short.

A woolen blanket is neither heavy, bulky, nor stiff. It is easily folded to fit the pack, and when properly arranged it forms a pad which protects the back of the packer from the corners of the cooking utensils and the ever-gouging steel traps and other hardware. If it gets wet it is easily dried without danger of burning, and if it does not get thoroughly dry it is warmer still than a cotton blanket.

The greatest thing about a wool blanket is that they are a pretty inexpensive addition to your pack. Here is a link to the wool Mexican blanket I own. For under $20, its a steal.

Never use a cotton blanket in the woods. Blankets made of cotton are cold to the touch, and do not retain the heat of the body as well as those made of wool. In addition to this they have the bad fault of not being as nearly impervious to sparks as woolen blankets. Now a man of the trail does not sleep with his feet towards the fire like the pioneer scout of border fiction, but he lies by the side of the fire, where he will get the benefit of its heat, and sometimes he rolls closer than he should for safety.

How large of a blanket do you need?

The blankets we buy for use on the bed are double or multi layered, but for camp use single layered blankets are preferable. They should be of generous size, for you won’t be able sleep comfortably if you have to constantly pull your knees up against your chin. What is more, the blankets should cover your head as well as your feet, so they should be a foot and a half longer than the user’s height. This is key due to the amount of heat lost from the head and feet (especially important for cold weather locations). They should also be wide — six feet should work, but any less and you may be tugging to cover yourself on a chilly night. This assures you enough space to create a makeshift sleeping bag by wrapping the blanket around your entire body.

But when zero weather is to be contended with woolen blankets must take a back seat for the blankets woven from strips of rabbit fur. Learn to make your own!