Edited sentence: An easier way to put it is when an object gets so hot that it is technically not a temperature.But the chances are this will not happen for trillions of years and that is if it happens so don't worry too much about dying from a kugelblitz.It is a pretty cool thing and if it where to happen then the earth as we know it would most certainly end.Or at least some of the species on it would die from all the energy and the radiation produced.This means that it will instantly become a black hole and this is what kugelblitz is