A bolt of icy frost forming a line 100 feet long and 5 feet wide blasts out from you in a direction you choose. Each creature in the line must make a Dexterity saving throw. A creature takes 6d6 cold damage on a failed save, or half as much damage on a successful one. A creature must also make this saving throw when it enters the line for the first time on a turn or ends its turn there.
As a bonus action while the spell persists, you can change the direction of the line. After you do so, each creature in the line must make a Dexterity saving throw, taking 6d6 cold damage on a failed save, or half as much on a successful one.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the damage increases by 1d6 for each slot level above 4th.