Fire Shield

Duration: 10 minutes, Concentration
Flames wreathe your body, shedding bright light
in a 10 ft radius and dim light for an extra 10 ft.
The flames provide you with a warm shield or a
chill shield. The warm shield grants resistance
to cold damage, and the chill shield grants
resistance to fire damage. In addition, whenever
a creature within 5 ft of you hits you with a
melee attack, the shield erupts with flame. The
attacker takes 2d8 fire damage from a warm
shield, or 2d8 cold dam