You searched for: “hypothermia
hyperthermia, hypothermia
hyperthermia (high" puhr THUR mee uh) (noun)
Unusually high body temperature: The doctors were worried because the patient seemed very hot as if suffering from hyperthermia.
hypothermia (high" puh THUR mee uh) (noun)
Abnormally low body temperature: People who enjoy hiking in the winter need to be very careful that they don't develop hypothermia and frostbite.

The doctors were very worried about Josie's well-being because her temperatures kept fluctuating between hyperthermia and hypothermia without a medical explanation.

hypothermia
A body temperature significantly less than 98.6°F (37°C).