All subjects who have subarachnoid hemorrhage from undetermined source, such as angiogram negative subarachnoid hemorrhage, those who have a reliable neurological exam such as Hunt and Hess grade 1-3 subarachnoid hemorrhage subjects, and those who are intubated, but require minimal sedation and therefore have a consistent neurological exam will be excluded from the study. Also, any subject that has a body temperature of less then 32 degrees Celsius will be excluded.