A defensive magical force surrounds you, manifesting as a thin layer of acid that covers you entirely. You gain 2d4+1 temporary hit points for the duration. If a creature hits you with a melee attack while you have these hit points, and the creature takes 2d4+1 acid damage. 

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, both the temporary hit points and the acid damage increase by 2d4+1 for each slot.