We are moving countries and want to take a couple of tins of powder with us on the aeroplane to use at the destination country. Is it safe to put it in hold luggage? I'm thinking of the very low temperatures and wondering whether it could damage the powder? If so, is it possible to take a couple of unopened tins in my hand luggage. My baby is fed breast and formula, so not a problem when flying (i am going to breast feed exclusively during the flight).