Plain English Meaning
The engine is running hotter than it should. If it stays too hot for too long, it can be damaged or quit running.
Full Definition
A condition in which an aircraft engine's operating temperature rises above its normal range, typically indicated by cylinder head temperature (CHT) or oil temperature exceeding manufacturer limits. Causes include prolonged high-power climbs, low airspeed reducing cooling airflow, lean fuel mixtures, low oil quantity, or restricted cooling air paths. Sustained overheating can lead to detonation, pre-ignition, loss of power, accelerated engine wear, and in cases .