It's OK—hang loose and stay cool.

没事儿，你要镇定，要冷静。

《牛津词典》

Let the braided hair hang loose on your collar.

让两条麻花辫松垂在你的衣领前。

youdao

Let's forget the exam, we'll go to the student union and just hang loose.

别再惦记着考试了。我们去学生会轻松一下。

youdao

To hang ten, or just hang loose, with fellow surfers, living near the best swells and breaks is where following your bliss will lead.

BBC: Living in: Surfing regions

Governor BLAGOJEVICH: Just hang loose.

NPR: Ill. High Court Rejects Attempt To Remove Governor

Hold on, just hang loose.

NPR: Ill. High Court Rejects Attempt To Remove Governor