A Power of Attorney only gives someone the ability to deal with your finances and assets. It does not give a person the right to make medical decisions for you.
British Columbia has passed legislation which allows you to appoint someone to make medical and personal care decisions for you and to outline your wishes if you are suffering from a terminal illness. This new document is known as a Representation Agreement.
The law states that if you are unable to make medical decisions for yourself, then your spouse is allowed to make those decisions for you in an emergency and if your spouse is not available, then your children. If your children are under age and your parents are still alive, then your parents would have the ability to make medical decisions for you.
However if you anticipate that your children would have difficulty coming to an agreement concerning your medical care or personal care, you may wish to appoint one or two of your children to be the decision makers for you concerning your health care and personal care. You may also appoint your spouse as your personal representative, but allow a third party, such as a child, to act as a monitor to ensure they are acting in your best interest. You may also want one person to take care of personal care decisions such as diet and hygiene, with another person assuming ultimate responsibility for major health decisions.