Heat transfer and its role in fire behavior
As those who have undergone a study of physics will most probably know, there are three methods of heat transfer. They are mainly conduction, convection and radiation. Other then this three methods there is still direct flame impingement to take into account.
Conduction is a process of heat transfer where heat travels through actual contact of the vibrating molecules. The more energetic molecules vibrate more vigorously, jostling the neighboring molecules. This jostling of neighboring molecules transfer heat energy as the jostling causes these molecules to vibrate more vigorously as well. Due to the close proximity of molecules in a solid, conduction is most noticeable in solids. The importance of thermal conductivity is most prominent in the role of setting fires in solids. In the case of metals, having a much higher thermal conductivity compared to non-metals in general, heat spreads rapidly to unheated areas. If these areas get into contact with an ignitable fuel, it will cause a fire at a distance from the initial heat source. For non-metals, most notably easily ignitable fuels like wood, heat tends to accumulate on the surface, raising the local temperature possibly to its ignition temperature, thus the fire will not be expected to occur at a distance from the initial heat source.