From Longman Dictionary of Contemporary Englishkeep your coolkeep your coolCALMto remain calm in a frightening or difficult situation I must keep my cool, she thought; losing my temper isn’t going to help. → cool
Examples from the Corpus
keep your cool• Kick the day into action with refreshing Celsius Body Splash Opposite, below: keep your cool even when working up a sweat.• Instead, Dukakis kept his cool and sealed his candidacy's doom.• He should go out and have a beer with you, not just keep his cool with the unit...• Oxford kept their cool though and came up with a winner 5 minutes from time.• The waitress was really busy, but she kept her cool.• You've got to keep your cool, you've got to be strong in the head.• One of the best tips is to keep your cool.• She'd fancied him for ages and when he asked her out she managed to keep her cool even though she felt faint.• Weaver keeps his cool while all those around him are losing theirs. 