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.
It is very important to bear in mind though that the temperature rankings are overviews for recommendation only. Because, much like spicy food, consuming a jalapeno pepper for some isn't really a big deal ... but for others eating one would certainly seem like it would melt the skin straight off their tongue. The exact same goes with a sleeping bag. A +20 level rating would indicate that for most the bag would certainly be cozy sufficient. The most effective way to pick a cozy enough bag is to go with one that handles a 10 degree chillier weather condition than what you're anticipating to be sleeping in. Selecting in that manner needs to have you ... covered. (No pun planned.) And once more of course, appropriate sleep wear should fit the chillier or warmer demands you may have.
If the sleep bags that you are taking a look at have not embraced the EN requirement, do not flip out. You could go by their temperature level measurement. The only difference is that these dimensions are to be used as a guideline just and do not think about the male/female distinction. Obtain a rest bag with added loft and also a reduced temperature level number if you're like me as well as are usually chilly whenever you sleep. The reduced the number, the cooler the exterior ambient temperature level can be where the bag will keep you cozy.