打退堂鼓

Jacky: How was your day? Did you ride the roller coaster (过山车)?

Ella: No. I got cold feet at the last minute (最后关头).

你在害怕或者胆怯的时候手脚是不是凉的呢？所以get cold feet 用来形容因为害怕而打了退堂鼓还真是很贴切的。