This systematic review examines whether preventing hypothermia during surgery prevents postoperative complications and thereby improves outcomes for patients. Twenty-six randomized controlled trials were identified, and data extraction and assessment of study quality were carried out by two researchers independently. The results of studies with similar patients, surgical procedures, and outcomes were pooled. Outcomes measured included postoperative pain levels, thermal comfort, and treatment costs. Postoperative complications identified were shivering, cardiac events, need for blood transfusion, wound infections, and pressure ulcers. The majority of studies favored treatment.