Rectangle-shaped sleeping bags go as much back as the late 1800's when a mail order catalog pioneer Pryce Pryce-Jones came up with the suggestion to attach 2 rectangular carpets together with ties. He is taken into consideration to be the innovator of today's contemporary rectangular sleeping bag design. After the war he had several of these bags still left as well as made a decision to market them to the public.
In 1917 the zipper was developed and, of course, these made for a terrific seal for the rectangular sleeping bags allowing an individuals body warmth to remain trapped longer consequently keeping them warmer on those cold winter season evenings. Basically the term resting bag essentially suggests a safety bag for someone to rest in.
The shape of the real resting bag is to personal preference. The general selections are the normal rectangular form, the conical form, or the mommy bag. Some individuals might not such as the feel of sleeping in a regular rectangular shaped bag, favoring the closeness of a tapered one, whereas others may really feel too claustrophobic.