To build a fire, it helps to understand the basic principles of a fire. Fuel (in a nongaseous state) does not burn directly. When you apply heat to a fuel, it produces a gas. This gas, combined with oxygen in the air, burns.
Understanding the concept of the fire triangle is very important in correctly constructing and maintaining a fire. The three sides of the triangle represent air, heat and fuel. If you remove any of these, the fire will go out. The correct ratio of these components is very important for a fire to burn at its greatest capability. The only way to learn this ratio is to practice.
Site selection and preparation
You will have to decide what site and arrangement to use. Before building a fire consider the following:
• The area (terrain and climate) in which you are operating.
• The materials and tools available.
• How much time you have.
• Why you need a fire.
• How close is the enemy?
Look for a dry spot that:
• Is protected from the wind.
• Is suitably placed in relation to your shelter (if any).
• Will concentrate the heat in the direction you desire.
• Has a supply of wood or other fuel available.
If you are in a wooded or brush-covered area, clear the brush and scrape the surface soil from the spot you have selected. Clear a circle at least 1 metre in diametre so there is little chance of the fire spreading. If time allows, construct a fire wall using logs or rocks. This wall will help to reflector direct the heat where you want it. It will also reduce flying sparks and cut down on the amount of wind blowing into the fire. However, you will need enough wind to keep the fire burning.
CAUTION: Do not use wet or porous rocks as they may explode when heated.
In some situations, you may find that an underground fireplace will best meet your needs. It conceals the fire and serves well for cooking food. To make an underground fireplace or "Dakota fire hole":
• Dig a hole in the ground.
• On the upwind side of this hole, poke or dig a large connecting hole for ventilation.
• Build your fire in the hole as illustrated.
If you are in a snow-covered area, use green logs to make a dry base for your fire. Trees with wrist-sized trunks are easily broken in extreme cold. Cut or break several green logs and lay them side by side on top of the snow. Add one or two more layers. Place the top layer of logs opposite those below it.
