Fortify

Abjuration cantrip
Casting time: 1 action
Range: Self
Target: --
Components: V, S
Duration: Instantaneous
Classes: Cleric, Druid, Sorcerer, Wizard
Subclasses:

You make a sign of protection in the air before you. When you do, you gain 1d6 temporary hit points. While you have any temporary hit points remaining from this spell, you lose 1 at the start of each of your turns.

The temporary hit points granted by this spell increases by 1d6 when you reach 5th level (2d6), 11th level (3d6), and 17th level (4d6).