Has this cold weather made your home do anything unexpected?

I store a pile of boxes belonging to my adult son against the wall in the unused, back bedroom. I have the heat almost turned off back there since it is for storage only. Yesterday, I went to move the boxes and found that one was frozen to the wall! The box had acted like insulation and formed a vapor barrier allowing water to condense and freeze. I moved the boxes so they are not touching the wall and the problem is solved.
Houses here are built to take the cold. Our plumbing is buried deep in the ground and all plumbing is located well away from cold walls. What about your home? Do you need to worry about pipes freezing? Do you do anything to prepare? Do you leave cupboards mounted on outside walls open so food or cleaning supplies do not gel or freeze? Do people who live in warm climates do anything to their pools?