The body core temperatures of 31 patients suffering from severe cerebral lesions were measured. Evidence for the existence or nonexistence of circadian rhythms in these patients was found to be associated with diagnosis (acute versus chronic lesions), with the level of consciousness, and with neurological findings (such as best motor response and pupillary reaction), but not with heart rate, corneal reflex, initial Glasgow coma score (GCS), or outcome. This evidence came to light only after multiphasic mathematical transformations of the raw data.