Source: Unearthed Arcana 78 - Draconic Options
2nd-level evocation
Casting Time:
1 action
Range:
Self (15-foot cone)
Components:
S, M (a vial of meltwater)
Duration:
Instantaneous
A burst of icy cold energy emanates from you in a 30-foot cone. Each creature in that area must make a Constitution saving throw. On a failed save, a creature takes 3d8 cold damage and is covered in ice for 1 minute or until a creature uses its action to break the ice off itself or another creature. A creature covered in ice has its speed reduced to 0. On a successful save, a creature takes half as much damage with no additional effects.
At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, increase the cold damage by 1d8 for each slot level above 2nd.