N.S.
It depends on what you want it for. If you just want to give permission to someone to take your kids to the dr or hospital in case of an emergency while you are away, all you have to do is write on a piece of paper that so and so is authorized to get medical attention for your kids in case of an emergency and sign it in front of a notary and a witness and have the notary notarize it. Otherwise you may want to contact an attorney.