Also, I feel that shelter-building in a survival setting (whether self-imposed or not) is in a constant state of evolution. You may start with the most basic of shelters, but over time, you may well be adding on to the basic structure to improve it, or perhaps replace it altogether. You may start with a simple lean-to, perhaps creating walls a day later or building a second one on yet another day. You might even decide to enclose your fire altogether with various structures on all sides.

Learning individual types of shelter is not conducive to promoting a fluid evolutionary improvement of your campsite. Knowledge of the principles at work is needed. With this knowledge, the resources of your shelter site and time available to you will become your only limits.

Chapter 1

Shelter Fundamentals

Except in hot weather, as discussed further down, the main purpose of a shelter is preventing excessive heat loss. Heat can be lost through conduction when your body is touching a material that is colder than you. This can happen when you’re lying directly on cold ground, are wearing wet clothes or are covered in damp leaves.

Heat can also be lost through convection. Convection occurs because moisture evaporating off your skin requires heat. When you are sweating or wet and the wind blows over your skin, the liquid will evaporate, using heat from your body to do so.

Finally, heat is lost through radiation. Heat always flows from warmer to colder masses, so even on windless, dry days, if the air is cool, your body will lose heat by radiating it into the surrounding air much like a radiator will warm a cold house.

Extrapolating your basic shelter requirements from these three causes of heat loss, your shelter should be dry, insulated from the cold ground, windproof and surrounded by heat or sufficiently low-volume air so your body can easily heat it.

In the exceptional case where you’re trying to prevent moisture loss or heat build-up, such as what might happen on a hot summer’s day or in a desert, the same principles still apply, only the flow of heat is reversed. You must avoid conduction of heat by not touching hot objects and use convection to keep the body cool (yet in such a way you don’t lose too much moisture). This is done by wearing appropriate clothing that allows perspiration, but keeps you cool and dry at the same time. Avoid radiation, again to avoid heat built-up and excessive loss of moisture by staying out of the sun.

Most of you will be concerned with heat loss, most of the time. So in this chapter, I will focus mainly on preventing heat loss and save the topics of moisture retention and overheating when covering specific shelters designed to combat those issues.

Shelter Starts with Good Clothing

Most people barely give their clothes a second thought beyond fashionability, comfort or suitability in particular social situations. However, the various clothes you decide to wear on any given day combine into your most important form of shelter.

Because clothes are so close-fitting to the body, choosing the right clothes to shelter you from the elements can be tricky at times as you strive to maintain a perfect balance between heat retention and loss. While you want to prevent most of your body heat from radiating into the surrounding air, you must also ensure that enough heat radiates away to prevent you from sweating. Sweating can make you wet, so you lose heat through either conduction (cold clothes) or convection (sweat evaporating off our skin or clothes).

This is best exemplified with people in extremely cold conditions dressing up extremely warmly, using multiple layers of clothes, then removing layers as soon as they undertake any form of strenuous activity. When the activity is over, they put the layers back on. I recall working in nothing more than a single merino wool base layer when sawing and chopping logs for my fire in the Yukon winter at –50°F!

This balance between heat and cold becomes even harder to maintain when factoring in rain.

I’m sure most of you have experienced dressing up in warm, waterproof clothes on a cold rainy day where you ended up wet and freezing because the waterproof coat caused you to sweat so much!

First of all, you have to realize that there are no perfect, all-weather clothes out there. They do not yet exist. Different clothing materials are better at some things than others. The key to maintaining that happy equilibrium between hot and cold then becomes wearing many different layers of clothes, combining the best qualities of different materials. This includes clothes to wick away your sweat, clothes to keep you warm and clothes to keep you dry and protected from wind. You then simply add or subtract layers as your circumstances change.

Below is a list of suggested clothing materials for different purposes:

Base Layer

Let’s start with a base layer. The purpose of this layer is to keep you dry by wicking away sweat. These would ordinarily be worn over underwear.

Cotton—Cotton can be very good at wicking away sweat, though it loses its insulative properties when wet and can cause you to feel cold once you slow down. Cotton can also take a long time to dry. It is best to avoid cotton if you have to dress warm and plan to engage in any activity at all.

Linen—Linen is very good at absorbing moisture so it can reduce the effects of sweating. It is most useful worn as both the inner and outer layer, as it dries extremely fast when exposed.

Wool—Wool, especially in thin merino wool clothes, is excellent at wicking away moisture and also tends to retain most of its ability to keep you warm, even when wet. This makes it one of my favorite materials for base layers. Modern manufacturing processes mean that wool clothes don’t have to be itchy as they once were and can be comfortably worn on bare skin.

Artificial fibers—Fibers such as polyester and polypropylene make excellent base layers and have emerged in many different shapes and forms in recent years. When choosing sizes, you’ll want to make sure that this layer is close-fitting and long enough to prevent gaps or exposed skin, even when bending or stretching.

Mid-Layer

The second group of layers, the mid-layer, is sometimes referred to as the insulation layer as its primary function is to retain body heat. These layers can be made out of a huge variety of materials.

Down-filled clothes—These are absolutely excellent at retaining heat. They’re also light and can easily be compressed for storage. They can be purchased with different amounts of filling, allowing you to choose a level of insulation as required. Though they are very warm, they lose most of their insulative ability when wet. Down-filled clothes are best used in extremely cold but dry environments.

Fleece—Fleece and its variants are excellent as a mid-layer, even when wet. The one major downside for the outdoor enthusiast is that clothes made out of this material are very flammable and can melt into the skin, causing horrific burns. Steer well clear of fire when wearing fleece, or remove the fleece or cover it up with less flammable clothes otherwise.

A large variety of fleece materials are becoming available in unlimited forms. Fleece clothes are available in different thicknesses. Personally, I prefer wearing more of the thin layers than fewer thick layers as it is easier to regulate temperature by adding or removing a thin layer.

Cotton—Often mixed with synthetic fibers, cotton is also a very common material for mid-layer clothes and is extremely versatile. Cotton clothes are useful as they can range from thinner (cooler) to thicker (warmer) clothes, allowing you to layer different types. Again, as with the base layer, the main drawback of cotton is that it becomes quite heavy and loses its ability to insulate if it becomes wet, though the mixing in of synthetic fibers helps to some extent. While you will presumably be wearing a coat over cotton tops in inclement weather, trousers are usually left exposed unless the weather is really bad. For that reason, cotton trousers (such as jeans) are best completely avoided. Instead, use trousers made from synthetic fibers, which are designed to remain light and dry quickly. You will also be able to buy such trousers with fleece lining or removable trouser legs.