Hot start

In aviation, a hot start is an adverse effect of a reaction engine being improperly started.

In a jet engine - be it a pure jet, a turbofan or a turboprop - a great amount of the air ingested by the engine runs around the combustion chamber or around its flame, instead of being mixed with fuel and burned. The purpose of this air is to keep the temperature of the chamber within its limits. If it weren't for this cooling effect, the chamber would get too hot because of the combustion, and it would then be burned or even melted.