During World War II, Heintges commanded the 3rd Battalion, 7th Infantry Regiment, 3rd Infantry Division and then commanded the 7th Regiment. He saw action in Sicily, Italy, southern France and Germany and his regiment captured Adolf Hitler’s Berghof in Berchtesgaden on 4 May 1945. Heintges took Hermann Göring's 1941 Mercedes-Benz 540K Cabriolet B for his personal use during the occupation.