John Young Templeton III ’37, of Bryn Mawr, Pa., a cardiothoracic surgeon and professor at Thomas Jefferson University who pioneered the use of the heart-lung machine, died of heart failure Tuesday, March 27, 2007, at Bryn Mawr Hospital. In the late forties, Dr. Templeton was a surgical resident at Jefferson. He assisted chief of surgery John H. Gibbon in the development of an artificial device to support patients’ heart and lung functions during open-heart surgery. The men successfully used Gibbon’s heart-lung machine in 1953 during an operation to repair a hole in the heart of an 18-year-old college student. During the next several years, Dr. Templeton performed many heart-valve surgeries and repaired congenital heart defects with the aid of the device. By the 1970s, he was using the machine in bypass surgeries to reroute blood around clogged arteries, improving blood flow and oxygen to the heart. Dr. Robert S. Boova, who was trained by Dr. Templeton at Jefferson in the 1980s, called that association “an experience of a lifetime.” Dr. Templeton’s legacy, he said, is the doctors he trained who lead surgery departments at distinguished institutions all over the country. Dr. Templeton was the recipient of the talent and technology he developed, his daughter Etheldra said. His father, a physician, died in his fifties from heart disease, which Dr. Templeton also developed. Bypass surgery performed by Boova prolonged his life, his daughter said. He hiked the Appalachian Trail and climbed Mount Katahdin in Maine before and after his surgery, she said, and enjoyed birding, crafting wooden canoes, and vacationing in his cabin in Quebec. Dr. Templeton was a graduate of Thomas Jefferson University Medical School. He interned at Jefferson, and then served in the Army Medical Corps in the States during World War II. After his discharge, he completed a residency at Jefferson and joined the surgical staff. From 1964 to 1967, he was professor of surgery at the University of Pennsylvania and was chief of surgery at Pennsylvania Hospital. He then returned to Jefferson and chaired the surgery department until 1969. He retired from Jefferson on his 70th birthday in 1987. The John Y. Templeton III Lectureship was established in his honor. Dr. Templeton received several grants to research new heart surgery techniques, and contributed more than eighty papers to medical literature. He was active in more than sixty professional and social organizations. He was a past president of the Jefferson Alumni Association and Jefferson’s medical staff and served on the university’s board. For sixty-two years he was married to Dorothy Fraley Templeton. They met at Jefferson, where she was an operating room nurse anesthetist. She died in 2005. Survivors include daughters Mary Brem, Etheldra, and Dorothy; a son, Bruce, 704 Conestoga Road, Bryn Mawr, Pa. 19010; a brother; two sisters; and three grandchildren. A son, John IV, died in 1964.