The next time you hit a creature with a melee weapon attack during the spell’s duration, your weapon glows blue and becomes extremely cold, and the attack deals an extra 2d6 cold damage to the target, and the target can't take reactions until the end of its next turn.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the initial extra damage dealt by the attack increases by 1d6 for each slot.