He was going to ask her but he got cold feet and said nothing.

他本来是想向她提出邀请的，可事到临头他却胆怯得什么也没有说。

《牛津词典》

People get cold feet. They get a space heater.

人们会手脚冰凉，于是买了小型供暖器，把它插在双交叉的延长线上。

youdao

Sally said I should try Bungee, but I had cold feet.

莎莉说我应该体验一下蹦极，但是我就是不敢。

youdao

But there is an expression to get cold feet that has nothing to do with cold or your feet.

VOA: special.2009.12.13

You are likely to get cold feet about being president when you understand the situation.

VOA: special.2009.12.13

As he pulled the door open, a cold rain rushed into the kitchen almost sweeping him from his feet.

VOA: special.2010.09.25

Atari got cold feet, and dropped the idea -- and the game -- before completion.

ENGADGET: blogger-avatar

That reduces the cancellation rates even if prices fall or buyers get cold feet.

WSJ: Deal of the Week: A High-Rising Exposure

But Greece's official creditors have their own reasons to get cold feet about another rescue package.

ECONOMIST: Rescuing Greece