- You may be looking for the song "Fever".
A fever is a medical symptom that describes an abnormally high increase in body temperature. It is most often a sign of systemic infection or sepsis.
Leonard McCoy ran a high fever in the episode The City on the Edge of Forever , as a bad side effect of an accidental drug overdose of cordrazine , thus becoming horribly dellusional and weak. He was nursed back to health by Edith Keeler. (TOS: "The City on the Edge of Forever")