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.
The ideal way to pick a cozy enough bag is to go with one that handles a 10 degree colder climate than exactly what you're anticipating to be resting in. The last most significant consideration in selecting a bag is the insulation that is made use of in that bag.
The trouble is that when I went to look for my "ideal bag" there was so many choices I really did not know which bag would certainly function best for me. One is the mommy bag and also the various other is the "old school" rectangular sleeping bag. The rectangular sleeping bag isn't as tiny however given that it's not regular to be carrying it, other compared to somewhere in a car while obtaining to your designated destination, the thickness of the bag is not as big an issue.