 After medical school Heimlich served with the U.S. Navy in China during World War II.In January 1945, as a member of the US Navy Reserve, Lieutenant (junior grade) Heimlich was assigned to Camp Four of the Sino-American Special Technical Cooperative Organization (SACO) located at Xamba, Suiyuan Province in northern China, on the southern edge of the Gobe Desert.Officially he was the chief medical officer responsible for the well-being of American and Chinese military personnel at this camp, but in actuality he also took care of a wide array of medical issues for civilians in the small town.