I am a member of a grandparents raising grandchildren support group. One of the options one of our attorneys that sometimes come and give talks on our rights, is for a parent to give one of the grandparents the right to seek medical treatment and other specific things like enroll them in school, sigh them up for sports, and things like that. But it's through the court system and is signed by a judge and then the court clerk puts their seal on it.
In this instance the rights of the parents are intact but the grandparent is covered to manage the child's needs without the parent being there.
This is WHAT is important.
Even on field trips, in child care, at school...all those permission to treat notes are useless. Completely useless. The agency has the parents sign them to protect that agency. But in all reality I could sign a piece of paper with your name and say that your inlaw has the right to do anything. Even if it's notarized it's still useless, for the most part.
If your child needs to go to the ER or seek medical treatment what is going to happen is IF your child need emergency treatment the medical staff will decide what needs to be done and do it. They'll have their clerk call a judge and get a court order and just whatever they want. They won't accept a piece of paper that is not worth the cost of the piece of paper.
One of our attorneys told us that their committee had written a law that had just been voted in where the parents can go to the courthouse and get an order that specifically gives a certain person the legal right to represent you in the case of an emergency. This law does NOT give the specific person the right to do anything you don't specifically put in the order and you can specify that it is totally of your choice and can be terminated at any time but it should have an expiration date on it.
Something like this. But having it done through the court clerk they have absolute permission to do what you've said they can do. If you just send a piece of paper and your child needs medical treatment the docs will do what they want even if you are on the phone telling them no. They have NO idea if you are truly that child's parent or some neighbor to the grandparents that is making something up.
"I, my name here, give, their name here, permission to seek emergency medical attention for my child, child's name here, on their trip from, place goes here, to, place goes here, then back to my home by, last date of trip goes here.
I give this permission for, their name goes here, to also...whatever you think might come up.
This permission is for a limited time in regards to this specific trip. This order expires on, or before, month, day, year."