Carbon monoxide poisoning is a serious illness, typically resulting from a natural gas leak or faulty automobile fuel system. Natural gas also includes a pungent odorifious agent that produces the "gas leak smell."

If you suspect a gas leak, leave the area immediately, then call Laclede Gas Company immediately at (314) 621-6960, 24 hours.

If you feel symptoms of carbon monoxide poisoning, leave the area/building you are in, and call 911 to reach the St. Louis Fire Department for emergency help.