It sounds really stupid at first, but it ain't necessarily so. I am quite certain that the guests bring with them lots and lots of blankets, sweaters, and other coverings, all of which are flammable, and some of which can produce toxic fumes. If the smoker mentioned in the story had instead tried to hide his ciggie by dropping the still-lit butt onto the floor, and managed to get it stuck in a blanket instead - one made of synthetics - the consequences might have been much worse. After all, fires are used for warmth and etc. in igloos, which are also made out of ice and snow.