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.
Semi-Rectangular: I call this the cross. This backpacking bag is rectangle-shaped ahead and afterwards slenders along towards the feet. With this type, you obtain added space, but not as much weight as a true rectangular resting bag. For those who are claustrophobic, like me; we can reach sleep a little better inside a bag with added room in it and still have some benefit from the form.
Remember that with time, from typical use, a treking sleeping bag will certainly lose its warming performance. This results from the fill obtaining a bit much more compressed. This will cause the "air pockets" to go away.