Why is it dangerous to return to a firework if you think the flame might have gone out?
Because it might not have gone out and it can be extremely dangerous because it could still go off!
A flashover is the near simultaneous ignition of all combustible material in an enclosed area. It is the most dangerous time of a fire. When the room bursts into flame, flashover has occurred. But since this question is categorized for USB flash drives, it might pertain to a brand name of a flash disk.
"Flame" is the visible energy when burning something. "Heat" is given off a flame and countless other things. Flame produces heat, but heat does not always generate from flame, and heat almost never produces flame (friction might count). And if you want the definitions: HEAT: a form of energy that is transferred by a difference in temperature. FLAME: the process of combustion of materials producing heat and light and (often) smoke. If you want to…