For a less technical, more soft and fuzzy answer--yes, radiators do get warm, although not to the point of being concerned about burns from accidental contact. (I once had a cat that slept on the radiator fins in the winter. The sharp fins gouging her stomach can't have been comfortable.) The warm radiator is a wonderful feature when you come in to the house wet and cold and need to warm your hands quickly. It is also useful as a towel warmer and to dry things. The radiators (obviously) take up a lot of room and they are terribly expensive to replace. Fortunately, they do not need to be replaced very often.