Mild Hypothermia and Supplemental Magnesium Sulfate Infusion in Severe Traumatic Brain Injury (TBI) Subjects

Inclusion Criteria: 1. Adult males or females ≥ 18 years of age 2. Subjects with Traumatic Brain Injury and a post-resuscitation Glasgow Coma Score (GCS) ≤ 8 3. In-hospital and screened within 7 hours of injury. 4. Able to obtain legally effective written consent from authorized representative 5. Patients who are intubated and on mechanical ventilation 6. Admitted to ICU Exclusion Criteria: 1. Bladder or rectal core temperature below 32C (89.6F) upon admission 2. Clinical brain death 3. Patients with open abdomens. 4. Multiple orthopedic injuries (\> 2 long bone fractures) 5. Persistent hypotension (systolic blood pressure \< 90mmHg) 6. Persistent hypoxia (O2 Saturation \< 94%) 7. Persistent metabolic acidosis (Lactic acid \> 5 mmol/L, arterial pH \< 7.25) 8. Positive serum pregnancy test 9. Cardiac arrhythmia with deleterious hemodynamic effects; heart block or myocardial damage (as shown on ECG) 10. History of abnormal renal function 11. Significant Co-morbidity (i.e. CAD;COPD; severe coagulopathy) 12. Pediatric patients (\< 18 years old)