It is important to keep a cool head in a crisis. = It is important to keep/stay cool in a crisis. 危急关头保持头脑冷静是很重要的。If you want to get out of here, you've got to keep a cool head.如果你想从这儿出去,你得保持冷静的头脑。It's important in this job to keep a cool head.做这种工作重要的是要保持冷静的头脑。