You'll need a change of clothes if you're staying overnight. 你要是在外面过夜,就需要带一套换洗的衣服。
I set off one morning with some food, a bottle of water, and a change of clothes in my bag.
You will need to bring at least two changes of clothes.
Patients on this ward are given a change of clothes daily.
I always keep a change of clothes in my locker at work.
See also: change noun (CLOTHES)