Space is very far away from the mount everest's top (approx. 91.2 kilometers) and its not cold it hasn't got a medium like air that can be colder relative to something so no thermic reaction can occur thus you can't feel temperature there, only the sunlight absorbed by your body and radiating away energy can change your temperature. The original question is that how could those ice cristals get up there if clouds that are the most common source of them in nature are way below it.