• A patient with central nervous system and systemic sarcoidosis had profound hypothermia and dementia with associated lymphadenopathy and hypernatremia. His capacity to develop fever remained; despite the persistent marked hypothermia, sweating and shivering in response to peripheral heating and cooling were maintained. Postmortem neuropathologic studies indicated that the hypothalamic region, generally considered to contain the primary temperature control, had been severely demaged by granulomatous sarcoid disease. These results confirm and extend previous findings of temperature disturbance in hypothalamic sarcoidosis and suggest that the integrity of the primary control of body temperature is not essential to fever production and "broad-band" regulation against environmental temperature extremes.