Temperature Control With an Esophageal Cooling Device in Post Cardiac Arrest Patients

Inclusion Criteria: * Patients admitted to the intensive care unit after resuscitation from an out-of-hospital cardiac arrest. * Sustained return of spontaneous circulation (no chest compressions required for \>20 minutes) * Not obeying commands to verbal instruction. * On mechanical ventilation via endotracheal tube or tracheotomy. Exclusion Criteria: * Known esophageal deformity (known esophageal varices, history of esophagectomy, previous swallowing disorders, achalasia, etc.) or evidence of esophageal trauma. * Known ingestion of acidic or caustic poisons within the prior 24 hours. * Patients with less than 40 kg of body mass. * Patients known to be pregnant. * Uncontrolled coagulopathy. * Documented intracranial hemorrhage. * Patients presenting to the intensive care unit with a temperature \< 35°C. * Time from collapse to return of spontaneous circulation \> 45 minutes or unknown. * Time from collapse to starting chest compressions \> 10 minutes or unknown. * Time from collapse to assessment for enrollment \> 12 hours. * Patients thought to have a very low chance of surviving the next 48 hours as assessed by the research team.