Lose your temper and the argument stops being about the topic. It’s about your temper now.

Anger changes the subject against your will. Whatever you were right about vanishes, and the conversation becomes a discussion of how you behaved, which is a discussion you cannot win. Everybody present will remember the shouting and forget the reason, and the person opposite you gets handed an easy exit. Control is not about being calm inside, only about what gets out.

Learn your early signals: the hot face, the faster talking, the urge to cut in. When one arrives, say you need five minutes and leave the room. Come back with the same point and watch it land properly.