have a low boiling point

have a low boiling point

To tend to become angry quickly or with little provocation. "Boiling point" here refers to one's limit in patience, temper, or equanimity, after which one loses control of one's emotions. (Likened to the temperature at which a given liquid boils.) A: "I can't believe Doug got so angry about such a minor mishap." B: "Yeah, he really has a low boiling point."
See also: boiling, have, low, point
Farlex Dictionary of Idioms.

have a low boiling point

Fig. to anger easily. Be nice to John. He's upset and has a low boiling point. Mr. Jones sure has a low boiling point. I hardly said anything, and he got angry.
See also: boiling, have, low, point
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • boiling point
  • reach (a) boiling point
  • reach boiling point
  • fly into a temper
  • dummy spit
  • do (one's) block
  • fly off the handle
  • fly off the handle, to
  • boiling mad
  • lose (one's) temper