The phrase "most hot-headed" refers to someone who is impulsive, quick-tempered, and easily angered. Some antonyms for this phrase could include "calm," "cool-headed," "level-headed," and "composed." People who possess these qualities are less likely to react emotionally to a situation and are more likely to think rationally before responding. Some additional antonyms for "most hot-headed" might include "unemotional," "detached," "innocuous," and "indifferent." These words all imply that someone is able to approach a situation without letting their emotions get the best of them and can think logically without being overwhelmed by feelings of anger or frustration.