Chillwind

You afflict one creature you can see within range with chilling wind that cripples them. The creature must make a Constitution Saving Throw, on a failure taking 1d6 cold damage and having their speed halved until the end of their next turn. In addition, their body is crippled with frostbite. At the start of each of its turns until the spell ends, the target must make a Constitution saving throw. On a failed save, it takes 1d6 cold damage, and so long as it is frostbitten, it's speed is halved. On a successful save, the spell ends. 

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the initial extra damage dealt by the attack increases by 1d6 for each slot.