'overheat' originates from the prefix 'over-' meaning 'excessively' and the word 'heat' from Old English 'hǣtan', meaning 'to make hot'.

'hǣtan' transformed into the Middle English word 'heaten', and eventually became the modern English word 'heat'.

Initially, it meant 'to make hot', but over time it evolved into its current meaning of 'to become excessively hot'.