They were , in fact that bedding was inherited from Instead of covering up with a fluffy blanket, most people slept in the same bed as the rest of the household, farm animals included . But as fabric became cheaper and blankets more accessible, they became household items. Now, even in tropical places, many people cover themselves with at least something during the night, with the exception of some nomadic cultures near the Equator. Part of the reason is that the body really does need extra warmth at night.