The purpose of this study was to evaluate various interventions used for rewarming patients with post-anesthetic hypothermia and to determine which treatments are most effective. Hypothermia is a potential complication that is seen in many patients post-operatively. It is defined as any temperature below 35 degrees Celsius (C) or 95.8 degrees Fahrenheit (F). The combination of anesthesia, cold room temperatures, and compromised patients predisposes them to hypothermia. Physicians and nurses need to understand the potential complications that can occur if patients are left to rewarm themselves passively. Many strategies are available to help patients achieve normothermia. In this review of research, the physiology of thermoregulation, complications of, and treatments for hypothermia are presented.