Yes - but only after exiting the home! CO is an odorless, tasteless, invisible gas. CO detectors are very sensitive and designed to alert occupants before CO reaches dangerous levels. If your detectors go off, call 911 and evacuate the home. Be sure to notify them if anyone in the house is experiencing flu-like symptoms. The Fire Department has specialized equipment to detect and measure amounts of CO in your home. Please do not open doors and windows before the Fire Department arrives, because this makes it difficult to determine the cause of any CO that may be present. Never hesitate to call us.