What is the heating of an organic substance without the addition of external heat called?

The phenomenon of heating an organic substance without the addition of external heat is known as spontaneous combustion. This occurs when a material self-ignites as a result of an increase in temperature caused by internal factors such as chemical reactions, oxidation, or microbial activity.

In the case of organic substances, particularly those that can oxidize readily (like certain oils or materials containing high fat content), they can heat up due to these processes, sometimes reaching their ignition temperature and igniting spontaneously. This is a critical concept in fire safety and inspection, as it highlights the importance of managing combustible materials to prevent accidental fires.

Understanding spontaneous combustion is crucial for fire inspectors because it emphasizes the potential hazards associated with improperly stored materials that may not seem threatening at first glance, yet can lead to dangerous fire situations without any external spark or flame being present.