Ice Block

6th-level Conjuration
Casting Time: 1 reaction
Range: Self
Components: VS
Duration: 1 round

As a reaction when you take damage, you can entomb yourself in ice, which melts away at the end of your next turn. You immediately gain 150 temporary hit points, which take as much of the triggering damage as possible. While you have temporary hit points from this spell, you are frozen. The spell ends at the end of your next turn, and you lose any remaining temporary hit points from this spell. If these temporary hit points are reduced to 0 before the end of your next turn, the spell ends prematurely.
At Higher Levels. When you cast this spell using a spell slot of 7th level or higher, you gain an additional 50 temporary hit points for each slot above 6th.

Source: Homebrew