What is the primary source of heat in a fire?

The primary source of heat in a fire is combustion. This process occurs when combustible materials react with an oxidizing agent, typically oxygen, producing heat, light, and various reaction byproducts. During combustion, chemical bonds in the fuel are broken, releasing energy, which raises the temperature of the surrounding materials and creates the heat necessary for sustaining the fire.

Combustion is at the heart of the fire triangle, which identifies the three essential elements of fire: fuel, heat, and oxygen. Without combustion, the fire cannot exist, as it is the mechanism that ignites and maintains the fire by producing the heat required to continue the chain reaction.

Other options, while related to heat transfer and the processes around fire, do not serve as the primary source of heat produced in a fire scenario. For instance, radiation describes how heat can be transferred through infrared radiation and does not generate heat by itself, but rather conveys heat from the fire to nearby objects. Friction involves work performed against the resistance of materials and may produce heat, but it is not the fundamental source in a fire context. Conduction refers to the transfer of heat through materials, which occurs after heat has been generated, rather than being a source of heat generation itself. Thus, combustion