have a cool head

You have to keep a cool head in case you hurt yourself.

你万一受伤,一定要保持镇定.

These are high pressure situations and you have to keep a cool head.

在高压力的情况下你必须保持冷静的头脑。

You have to keep a cool head in these volatile situations.

在这些易变的情况下你得保持冷静.

Pretty cool of CNBC to let the destitute have a voice for their stock picks. Or this one: He likely has his head in a pile of coke in his free time and his opinions are laughable.

CNBC太酷了，还能让穷人谈选股。或这则：他很可能在闲时把自己的脑袋塞进了一堆焦炭里面，他的意见真是令人发笑。

A commander needs to have a cool head.

指挥员需要有一个冷静的头脑。

Your job is dangerous, you have to keep a cool head in case you hurt yourself.

你的工作有危险性，你必须保持冷静的头脑，以免伤害自己。