John Corley.. age 10, of Peterborough, Ontario, for his question.  

What is spontaneous combustion?

Combustion is the burning process. It happens when fuels such as paper and rages, wood and hay get hot enough to reach their kindling points. When we put a match to a campfire, the fuels reach kindling point and start to blaze. This is ordinary combustion. A spontaneous event happens by itself, without any help from us. Spontaneous combustion is a fire that breaks out by itself. A fuel gets hot enough to burn without the help of a match.

Certain chemicals and certain bacteria give off heat. A pile of paint rags shut away from the cooling air can get hot enough to start a fare. Bacteria in a haystack may give off enough heat to start a fire. These blazing events are examples of spontaneous combustion.