If there is a medical emergency, then it is morally permissible to administer care without express consent.
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Every human being of adult years and sound mind has a right to determine what shall be done with his own body; and a surgeon who performs an operation without his patient’s consent commits and assault for which he is liable in damages. This is true, except in cases of emergency where the patient is unconscious and where it is necessary to operate before consent can be obtained. - Justice Cardozo