Elemental Cloak

You summon the forces of an element of your choosing to harm those who approach you. Choose either cold, fire, or lightning. Any creature that enters a space within 5 feet or starts its turn within of you must make a Dexterity saving throw, taking 2d4 damage of your chosen type on a failure or half as much as a success. 

At Higher Levels. When you cast this spell with a spell slot of 3rd level or higher, the damage increases by 1d4 for each slot level above 2nd.