To keep your head is to stay calm when everybody else is panicking. Keep your head, whatever happens.
It is praise for the moment rather than for the person, since anybody can lose it. The famous line about keeping your head when all about you are losing theirs is Kipling.
1phrasekeep your headTo stay calm when everybody else is panicking.
“Keep your head when the alarm goes and everybody else will follow you.”
keep your head is a phrase.
Practised in Idioms