Elemental Aura

Invisible elemental energy radiates from you in an aura with a 30-foot radius. Until the spell ends, the aura moves with you, centered on you. Choose a damage type: cold, fire, lightning, or poison. Each creature who starts its turn in the aura takes 1d4 damage of the type you choose. When you cast this spell, you can choose creatures you wish to be unaffected by this aura.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d4 for each slot level above 3rd.