A sleeping bag typically includes first and second opposed halves defining a sleeping compartment therebetween and which are connected in such a way to define an entrance aperture at an entrance side or end of the sleeping bag. The sleeping bag may include insulation. Very lightweight, compressible insulation materials, such as water fowl down, are extremely desirable since they are able to provide sufficient insulation while being light weight and easily compressed. When used as an insulation material in sleeping bags, the down is easily compressed from the outside by the weight of the bag materials and from the inside by the user pushing outward. Depending on conditions a user is expected to encounter, the user may select a particular sleeping bag having a limit rating that is suitable in the expected conditions.