The Collaborative International Dictionary of English v.0.48:
Hot-head \Hot"-head`\, n.
A violent, passionate person; a hasty or impetuous person;
as, the rant of a hot-head.
[1913 Webster]
Moby Thesaurus II by Grady Ward, 1.0:
60 Moby Thesaurus words for "hothead":
Mafioso, Tartar, Young Turk, bear, beast, beldam, berserk,
berserker, bomber, brute, crank, crosspatch, demon, devil, dragon,
feist, fiend, fire-eater, firebrand, fury, goon, gorilla,
grizzly bear, grouch, gunsel, hardnose, hell-raiser, hellcat,
hellhound, hellion, holy terror, hood, hoodlum, hotspur,
incendiary, killer, mad dog, madcap, monster, mugger, rapist,
revolutionary, savage, she-wolf, sorehead, spitfire, termagant,
terror, terrorist, tiger, tigress, tough, tough guy, ugly customer,
violent, virago, vixen, wild beast, witch, wolf