What does Boxing Day have to do with boxing?
hyperthermia hy·per·ther·mi·a (hī'pər-thûr'mē-ə)
Extremely high fever or body temperature, especially when therapeutically induced.
An abnormally high body temperature, usually resulting from infection, certain drugs and medications, or head injury. Hyperthermia is sometimes created intentionally to treat diseases, especially some cancers. Compare hypothermia.