The Fire Department will want to check it when they arrive, and help determine the source of the problem. Do not re-enter your home until the emergency responders have arrived, your home is aired out, and your CO alarm returns to normal operation. If you only have one carbon monoxide alarm, install it in the hallway near the sleeping area. Make sure you can hear it from every bedroom so it can awaken everyone if the alarm goes of while you are asleep. Additional alarms on each level of your home provide extra protection.
Carbon monoxide weighs about the same as air, and distributes evenly throughout a room.
A CO alarm will be effective if it's on the ceiling, near the baseboard, or anywhere in between. Pick a location where the alarm will stay clean, and out of children's reach. If you have any questions on carbon monoxide feel free to contact the Lake Forest Fire Prevention Bureau at 615-4238, and remember to Dial 911 for emergencies.