Fire is a combustion reaction between oxygen and fuel that typically produces heat, light and smoke. The resulting heat from the reaction can postpone or prevent the risk of hypothermia. Lighting a fire without a lighter or matches, e.g. by using natural flint and a rock or metal with tinder, is a frequent subject of both books on survival and in survival courses, often due to the lack of said materials if an individual was stranded. There is an emphasis placed on practicing fire-making skills before venturing into the wilderness. Producing fire under adverse conditions has been made much easier by the introduction of tools such as the solar spark lighter and the fire piston.
Fires are either started with a concentration of heat, as in the case of the solar spark lighter, or through a spark, as in the case of flint striking a rock or metal. Fires will often be put out if either there is excessive wind (such as either over fanning a fire, or strong winds), or if the fuel or environment is too wet to ignite.
Fire is presented as a tool meeting many survival needs. Along with the need that's mentioned above, it also disinfects water (through boiling and condensing), and can be used to cook and prevent illnesses in foods like animal meat. Another advantage that is presented through fire is an underlooked psychological boost through the sense of safety and protection it gives. In the wild, fire can provide a sensation of home, a focal point, in addition to being an essential energy source. Fire may deter wild animals from interfering with an individual, however wild animals may be attracted to the light and heat of a fire.
Fatwood is an excellent way of starting a fire.
It comes from pine trees and is the part of the pinetree which is absolutely packed full of its resin.
You find it at the part of the tree where the branches join the main trunk, sometimes you can find dead branches that have fallen off around the bottom of the tree, which still have the shoulder attached and where you can take your fatwood from.
Sometimes you may have to cut it out of the tree itself, but it is always in the area where the branch joins the tree.
Use a knife to shave shavings from it and use these shavings to ignite the spark