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.
If you see a +20 degree score that would certainly indicate that the bag should be cozy enough for temperatures that are 20 levels or warmer.. And if you see a - 20 level score then it has actually been figured out that the bag needs to be cozy sufficient for minus 20 degree climate.
I could confess that I have actually had one as well lots of experiences with that and also young boy, that was enough for me recognize that if I desire to truly want to enjoy my trips, finding the perfect resting bag for me is a top priority. The trouble is that when I went to look for my "ideal bag" there was so lots of choices I didn't recognize which bag would function best for me.