Thermal Implosion

Intertwined streaks of silver and red light flash from your pointed finger to a point you choose within range and then explodes into flame with a loud bang, followed by an icy implosion as it reaches its outer range. Each creature in a 20-foot-radius sphere must make a Dexterity saving throw. A target takes 4d6 Fire damage and 4d6 Cold damage on a failed save, or half as much damage on a successful one.

The fire spreads around corners, and the frost returns through them.

At Higher Levels: When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d6 fire damage and 1d6 ice damage for each spell slot above 3rd.