[Lourdes]

Hey!
Last semester I had this weird question during my exam. Unfortunately I cannot remember the exact way it was asked but that is what I still remember: What happens to the hydration sphere of a salt when I put it in the fridge/freezer?
I had no idea how to answer this question, does anybody know maybe what is meant by that?
Sorry for the lack of information, that is all I remember.
Thank you very much in advance!