Since Biblical times, heat injuries have been a major focus of military medical personnel. Heat illness accounts for considerable morbidity during recruit training and remains a common cause of preventable nontraumatic exertional death in the United States military. This brief report describes current regulations used by Army, Air Force, and Navy medical personnel to return active duty warfighters who are affected by a heat illness back to full duty. In addition, a description of the profile system used in evaluating the different body systems, and how it relates to military return to duty, are detailed. Current guidelines require clinical resolution, as well as a profile that that protects a soldier through repeated heat cycles, prior to returning to full duty. The Israeli Defense Force, in contrast, incorporates a heat tolerance test to return to duty those soldiers afflicted by heat stroke, which is briefly described. Future directions for U.S. military medicine are discussed.