Blood transfusion

Blood transfusion was the process of receiving blood products into the circulatory system.

The Monk mentioned that he would like to give the injured Eldred a blood transfusion, but Wulnoth did not understand what he meant. (TV: "A Battle of Wits")

The Eighth Doctor once gave the Fourth Doctor a blood transfusion direct from himself. He did so as his former self was dying from blood loss after a Vampire attack. (PROSE: The Eight Doctors)