While your college kids are home for the holidays it's a great time to encourage them to put some just-in-case legal documents in place. When children turn 18 and become adults, their parents are unable to legally act on their behalf without court intervention or the individual's express written consent. Accordingly, you should consider having your adult children put two legal documents in place: a health care directive and a power of attorney.
A health care directive would allow your child to choose an individual (i.e., you) to receive health care information and make health care decisions on their behalf should they be unable to speak for themselves. Due to HIPAA, even as a parent, you are no longer entitled to receive health care information or have any decision-making authority for your adult children. If you can only convince your "kids" to sign one document, this is the one I would highly recommend.
A power of attorney enables the attorney-in-fact (i.e., you) to transact business act on behalf of the principal (i.e., your child). This is especially useful when your child studies abroad. Having someone in the United States who can manage your child's affairs can be terrifically useful particularly with the time zone differences. It's also nice if you use a local bank without branches where your child attends college.
These are relatively simple documents that are powerful tools in the event of an unforeseen emergency.