Idiom of the day :- Keep one’s hair on
Usage, examples and definition of the Idiom :-
I’d panic if I lost my coat. Not Bob though. He’s determined to keep his hair on. That is, he’s going to stay relaxed and not get angry. ‘I’m going to remain calm and keep my hair on,’ Bob said. ‘It’s pointless to get upset over the loss of a fur coat, don’t you agree ?’