Mouth-to-mouth resuscitation
Mouth-to-mouth resuscitation was a resuscitation method where one placed their mouth against that of another and blew oxygen into the person's lungs to assist with respiration.
In 2268, an amnesiac Captain James T. Kirk performed cardiopulmonary resuscitation and mouth-to-mouth resuscitation on a boy who had become entangled in fishnets and sank to the bottom of a river on the planet Amerind. (TOS: "The Paradise Syndrome")