冷静点，淡定点，别发脾气
We use this expression to tell someone to not be angry or upset, which we think is unnecessary.
我们用这个表达告诉某人不要生气或难过，因为我们认为这没必要。
Keep your hair on, Mary. I wasn't saying that you should do anything dangerous.
冷静点，玛丽。我没有说要你去做危险的事。
Keep your hair on, Mum. You can hardly see the damage.
冷静点，妈妈。这东西上几乎看不出有什么损坏。
