I stand corrected about the Hookas burning
tobacco. Still with a red hot cherry sitting on top of tobacco with only foil between them is generating some serious heat. That sort of heat plus tobacco will still release some nasty nitrousamines and other chmicals, not as bad as actually burning tobacco but still no where near as benign as e-cigartte vapour I reckon. I'm sure there is some Carbon Monoxide in there too...