it's there if I want to fill it with leaves and make a matteress someday <img src="/forums/images/graemlins/grin.gif" alt="" />
Insulation must be thick enough to prevent convection of air currents to keep you comfortable.
That just gave me an idea, for an emergency bivy. Use one spaceblanket bivy (the closed bag type, not the flat sheet type). Then either use a breathable, thin bag, or nothing at all. Put the thin bag inside the spacebivy, then stuff leaves inbetween to form a thick insulative layer. Or, just stuff leaves inside the spacebivy and get in without the other layer between you and the leaves. Obviously only good with leaves or pine needles around. If it is winter with snow, you could pull the needles off the trees to form the insulated layer. Again, emergency only idea. Any thoughts?