Intraoperative Warming During Major Surgical Procedures Using the Esophageal Temperature Management System

Inclusion Criteria: * Provision of signed and dated informed consent form * Male or female, ages 18 years and older * Scheduled for major surgical procedures requiring general anesthesia and with no known contraindication to having an orogastric tube placed for the duration of the surgery * The time in the OR is expected to last at least 180 minutes Exclusion Criteria: * Esophageal strictures (risk of perforation) * Patients with known esophageal deformity or evidence of esophageal trauma (for example history of esophagectomy, previous swallowing disorders, achalasia, etc.) * Known ingestion of acidic or caustic poisons within the prior 24 hours. * Patients with \<40 kg of body mass * Coagulopathy * Severe facial trauma * Surgical procedures lasting less than 3 hours