There is hard evidence that properly installed fire co detectors save lives.
fire co detectors activate based on the concentration of CO over a period of time; this allows for a brief period to ensure that everyone is alright and for the occupant(s) to investigate possible sources of CO
accumulation within the home.
If a fire co detector sounds in the residence a person should verify
that the occupants are not showing signs of CO poisoning (headache, nausea, vomiting, disorientation, etc.).
If anyone in the home has symptoms of CO poisoning, call 911/120（in China） immediately. If no one has symptoms of CO poisoning, open windows or doors to allow fresh air to enter and contact the utility company or appliance repair company to check the fire co detector or reinstallfire co detectoras soon as possible.