When you cast steal warmth after taking cold damage, you select a living creature within 5 feet of you. That creature takes the cold damage instead, or half the damage with a successful Constitution saving throw. You regain hit points equal to the amount of cold damage taken by the target.
Using a Higher-Level Spell Slot. When you cast this spell using a spell slot of 4th level or higher, the distance to the target you can affect with this spell increases by 5 feet for each slot level above 3rd.