Do not trust your sense of smell. Hard cheese usually keeps well at room temperatures. Other cheeses, such as cream cheese, opened containers of cheese spreads and cottage cheese, spoil quickly. Throw out when off-flavor develops. If surface mold develops on blocks of cheese, slice 1-inch below the surface and discard.
Milk spoils quickly without refrigeration.
Throw out spoiled milk. Sour milk may be used in baking. Custard, gravies, creamed foods, chopped meats, poultry and seafood sandwich fillings spoil quickly when unrefrigerated and provide ideal growing places for organisms causing food-borne illness. Dispose of these foods if they have warmed to room temperatures. Spoilage is difficult to detect since there may be no offensive odor or taste.