+1 to that, take it out the bag and it'll burn out the element in the head. By turning the bag inside out however, your still getting the same ammount of air and the same burn times ( if there was more air, the fuel would burn faster, wouldnt last 23 hrs) so all your doing is changing the thermal dynamics of the bag and allowing the heat out. I get your point on the sleeping bag subject, wonder how much co they emit aswel