Pyrexia can exacerbate ischemic neuronal damage and physiological dysfunction after traumatic brain injury and subarachnoid hemorrhage.Fever also represent an important issue occurring in 78% of patients with acute cerebral damage admitted to intensive care unit (ICU). For those patients, normothermia is actually recommended in order to reduce secondary cerebral damage and to control intracranial pressure, that are known to worsen long term prognosis. Our primary endpoint is to maintain normothermia in patients with acute cerebral damage (axillary temperature < 38°C or internal temperature < 38,8°C) administering diclofenac. We will also investigate the corresponding behaviour of intracranial pressure and cerebral perfusion pressure.