Sode No Shirayuki is an ice-typed elemental Zanpakuto, much like Captain Hitsugaya’s. The bankai of the sword lowers the wielder’s body temperature to a deathless state, and then expands those ...

This means that, unlike other Soul Reapers who may have elemental Zanpakuto, Yamamoto and Hitsugaya are able to manifest and control their preferred element even without drawing their swords.