Surely a breaker can only detect over-current or short-to earth/neutral (which would also be an overcurrent I guess). If the thing just heats up and catches fi

Surely a breaker can only detect over-current or short-to earth/neutral (which would also be an overcurrent I guess). If the thing just heats up and catches fire, it might not trip the breaker. I meant overheating itself, not erroneously turning things off/on.