 The curve showed that the structural change from ice III to ice II was more likely to happen if the medium had previously been in the structural conformation of ice II.However, if a sample of ice III that had never been in the ice II state was obtained, it could be supercooled even below −70 °C without it changing into ice II.Conversely, however, any superheating of ice II was not possible in regards to retaining the same form.