A person who inhales carbon monoxide will not likely recover immediately when moved to good air. There is also the threat of burns. Kerosene heaters have an open flame. A fire can occur if fuel is spilled. Also, flammable vapors of many types from many sources can occur within a home or building.
Few people realize the vapors from tile cement can be very explosive.
It is not inconceivable for someone to use a space heater where tile cement is being put down or lacquers are being applied. Other sources include cleaning agents, adhesives, and some aerosol products. Any product using a solvent other than water is a potential source of fire or an explosion. There are other fire hazards, such as curtains, paper, carpets or anything in the home that is combustible. Carbon monoxide poisoning deserves the most attention.