To Study the Effect of Early Cooling in Acute Subdural Hematoma Patients

Inclusion Criteria: * Non-penetrating traumatic brain injury * Glasgow Coma Scale (GCS) motor score ≤5 (not following commands) * Estimated or known age 22-65 years * Acute subdural hematoma requiring emergent craniotomy within 6 hours of initial injury * Estimated time of injury to time to reach temp of 35°C\<6 hrs Exclusion Criteria: * Total GCS = 3 and bilateral fixed and dilated pupils * Following commands after an initial period of coma (GSC motor score of 6) * Known pre-existing neurological deficit (e.g., previous traumatic brain injury (TBI), stroke) * Concomitant spinal cord injury * Arrival temperature is \<35°C * Hemodynamic instability (i.e., mean arterial pressure (MAP)\<60 millimetres of mercury (mmHg) for 30 minutes) * Active cardiac dysrhythmia resulting in hemodynamic instability * Pregnancy * Duret hemorrhage * Prisoner or Ward of the State * Known history of clotting disorder (e.g., heparin induced thrombocytopenia, pulmonary embolism/deep venous thrombosis) * Injury to other body organ where hypothermia would be precluded because of bleeding risk (e.g., grade 3 liver laceration; bowel laceration; flail lung or international normalized ratio (INR) \>1.4) * Inability to obtain informed consent or utilize exception to informed consent for emergency research.