When biological material (cells, blood, tissues) is frozen, cryoprotectants are used to prevent the damage associated with the formation of ice during the freezing process. New polymeric cryoprotectants are emerging, alongside the established cryoprotectants, but how exactly they manage to control ice formation and growth is still largely unknown. This is especially true for PVA, a deceptively simple synthetic polymer that interacts with ice by means of mechanisms that have now been revealed at the atomistic level thanks to researchers from the University of Warwick.