Hamburger such as , due to the occasional initial improper preparation of the meat, so caution is needed during handling and cooking. Because of the potential for food-borne illness, the USDA recommends hamburgers be cooked to an internal temperature of . If cooked to this temperature, they are considered well-done. Burgers can also be made with patties made from ingredients other than beef. For example, a "turkey burger" uses ground turkey meat, a "chicken burger" uses ground chicken meat. A "buffalo burger" uses ground meat from a bison, and an "ostrich burger" is made from ground seasoned ostrich meat. A deer
Rudolf Hamburger Stalin's purges against enemies of the regime were at their height. More than a thousand German political refugees from Nazism were among the many Muscovites identified as Trotskyites and spies: in many cases they were summarily tried and shot. Ursula Hamburger was well aware of what was going on, but she herself never fell victim to Stalin's paranoia. Rudolf Hamburger subsequently wrote that his contribution to Soviet intelligence during the time in Poland was in effect restricted to the help he was able to give his wife. He involved himself in the installation of radio antennae and getting hold of