Glacial Fog

7th-level evocation (winter)

Casting Time: 1 action
Range: 100 feet
Components: V, S, M (crystalline statue of a polar bear worth at least 25 gp)
Duration: Concentration, up to 1 minute

As you cast this spell, a 30-foot-radius sphere centered on a point within range becomes covered in a frigid fog. Each creature that is in the area at the start of its turn while the spell remains in effect must make a Constitution saving throw. On a failed save, a creature takes 12d6 cold damage and gains one level of exhaustion, and it has disadvantage on Perception checks until the start of its next turn. On a successful save, the creature takes half the damage and ignores the other effects.

Stored devices and tools are all frozen by the fog: crossbow mechanisms become sluggish, weapons are stuck in scabbards, potions turn to ice, bag cords freeze together, and so forth. Such items require the application of heat for 1 round or longer in order to become useful again.

At Higher Levels. When you cast this spell using a spell slot of 8th level or higher, the damage increases by 1d6 for each slot level above 7th.