Obtaining informed consent is not always required. If an individual is considered unable to give informed consent, another person is generally authorized to give consent on his behalf, e.g., parents or legal guardians of a child (though in this circumstance the child may be required to provide informed assent) and conservators for the mentally disordered, or consent can be assumed through the doctrine of implied consent, e.g., when an unconscious person will die without immediate medical treatment.