[Randaddy]

Sleeping bag liners work and are much lighter than a second bag. Do you own a zero degree bag? I'm not sure why you would want to carry two sleeping bags, unless you already have them and can't spend any money, which I can totally relate to. If you own a zero bag you should consider wearing fleece pants and a down jacket when you sleep inside the bag. (Anyone who subscribes to the theory that less clothing in the bag is warmer is WRONG - please refer to the lawas of thermodynamics before commenting on this. It's bullshit propaganda put out by sleeping bag companies!)

If you are looking for a quality sleeping bag, I work for GoLite and we have two sales in Denver right now, selling 2010 bags at almost half price. We can put you in a zero degree, 800 fill down bag that's under four pounds for under $300... Feel free to PM me for details.

 

[Randaddy]

Obviously insulating warm layers are good, but I was under the understanding that shells just add bulk and disallow warmth from being reflected back to you from the bag. You tell me, I've never been so cold that I would try. I can't imagine a comfortable way for me to fit my shells inside my mummies either.

When you wear clothing inside the bag you keep more heat from ever escaping your body - even in a tight mummy bag there is usually some air space that steals heat from you.

I know people that design sleeping bags for a couple of major manufacturers and they both subscribe to the "heat reflects back" theory. I just don't get it. More layers will equal more warmth. Think of the down jacket as just more sleeping bag. Less heat leaves your body and your body stays warmer. I have tested this on consecutive 0 degree nights in a quincy and reported much more warmth with my clothing on.

It's funny how gear geeks perpetuate these rumors founded in bad science.