Your loved ones will need a Power of Attorney in order to handle your financial affairs while you are alive but incapacitated. They will need a Representation Agreement to care for your health care needs. A Power of Attorney is not enough to give someone the legal authority to make decisions and give directions to your doctors about your medical treatment.
It is also important to make sure your wishes are followed for your health care and living arrangements with aging. Your spouse, ex-spouse, children, step-children and friends might not agree with each other. They also might not share your values. If you put in place a proper Representation Agreement, there can be no disagreements and no overriding of your wishes, because your decisions and directions are legally binding.