make one's blood boil

Example: “It makes my blood boil when people litter in the park.”

Origin: A fossil of a physiological theory people once took entirely seriously. Classical and medieval medicine held that temperament was governed by four humors, that anger was hot and associated with yellow bile, and that rage produced real thermal change in the body — Aristotle, defining anger in De Anima, described it as a boiling of the blood around the heart, offered not as a metaphor but as the physical account of what anger is. That framework governed European medicine for roughly two thousand years, and English is still full of its wreckage: hot-tempered, hot-headed, cold-blooded, in cold blood, a warm heart, humor itself. The idiom survives because the sensation it names is real even though the explanation has been discarded.