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
Hamburger critics like Josh Ozersky, a food editor for "New York Magazine", claim that this sandwich was not a hamburger because the bread was toasted. One of the earliest claims comes from Charlie Nagreen, who in 1885 sold a meatball between two slices of bread at the Seymour Fair now sometimes called the Outagamie County Fair. The Seymour Community Historical Society of Seymour, Wisconsin, credits Nagreen, now known as "Hamburger Charlie", with the invention. Nagreen was fifteen when he was reportedly selling pork sandwiches at the 1885 Seymour Fair, made so customers could eat while walking. The Historical Society explains that