Actually freezing people was a method used at the Central Plains in many places, for example when somebody was severely injured and was in need of a cure that couldn't be acquired immediately. This person would be frozen and put into a suspended animation state to delay the coming of death.
Lu Li's grandpa was injured by a ferocious kind of voodoo at the Southern Land of Voodoo and came back with a grave injury. He was also frozen in the side chamber where the Blood Pond of God was located. Lu Li even saw the cold air coming out from that side chamber…
Bai Qiuxue was also frozen today and for nobody knew how many years. According to Chee-ker, nobody could cure the Immortal's Perish, as such, the abbot at the Great Buddha Temple might not be able to provide a cure.