Some U.S. companies of backpacking sleeping bags have complied with the European Standard (EN 13537) technique of temperature level screening. Without entering into excessive deepness about exactly how they reach these numbers, generally they check the best sleeping bags under strict standards using a clothed dummy sporting long underwear and also a hat. Sensors on the mannequin document temperature readings.
The other sacrifice is the size or thickness of the bag. A mummy sleeping bag essentially will certainly be much smaller sized for bring around which is why it is a preference for many backpackers/hikers. The rectangular resting bag isn't as small yet because it's not common to be lugging it, apart from somewhere in a vehicle while getting to your intended location, the bulkiness of the bag is not as large a problem.
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.