Armor of Elemental Fire - Elemental Armor

You form a pillar of roaring flames around a creature you can see. The creature is immune to fire damage and has 20 temporary hit points, which cannot be reduced by fire damage, and deals 1d4+20 fire damage to a creature that deals damage to the temporary hit points.

At higher levels. The temporary hit points and modifier to the fire damage increase by 10 for each spell slot above 2nd.

Armor of Elemental Air, Armor of Elemental Fire, Armor of Elemental Earth, Armor of Elemental Water, and Armor of Elemental Ice are one spell for the purpose of preparing, called Elemental Armor.  I apologize for not making them a single spell from the beginning.