Hothead

wiktionary

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From hot +‎ head. Compare English hotbrain(“a hothead”); Middle English hot-heorte, hat-heorte(“anger”), Old English hātheort(“furious, angry, irascible, passionate, ardent”, literally “hot-heart”).

etymonline

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hothead (n.)

"short-tempered person," 1650s, from hot in the figurative sense + head (n.); Johnson's dictionary also lists hotmouthed "headstrong, ungovernable;" Elizabethan English had hot-brain "hothead" (c. 1600); and Old English had hatheort "anger, rage," literally "hot heart."