How do you imagine that? Loss of consciousness from breathing butane may occur in 30 - 60 seconds. When I tried rebreathing plain air in a sealed plastic bag, I never got high CO2 concentrations in such a small time interval. Depending on the volume of air inside, it took 1.5 - 3 minutes to reach moderate (and bearable) sense of suffocation. Hence if there is some panic due to CO2 buildup with the OP's method, it would probably appear after consciousness is lost. How is this even possible? Can an unconscious person experience panic or can CO2 somehow make you regain consciousness to a degree that allows panic state? Do we have any actual studies that confirm either outcome?
