OXON HILL, Md. (CBSDC) - An Oxon Hill family survived a carbon monoxide threat Tuesday because of proper home protection, prompting Prince George’s County fire officials to remind homeowners to follow their lead.

The family of four was awakened around 2:45 a.m. on Tuesday after their carbon monoxide detector sent out an audible alert when CO levels reached an unhealthy level in their home.

A 911 call was placed and minutes later firefighters from Oxon Hill arrived to investigate the alarm at 532 Wilson Bridge Dr.

Firefighters used gas detection equipment to find CO levels at 45 parts per million. Any reading over five to ten ppm can be unhealthy. The amount of exposure time before you feel the effects shrinks as the parts per million grow, according to fire officials.

Officials say the family – a mother and her three sons – were already feeling early side effects of carbon monoxide exposure when help arrived, including headaches and grogginess. They were treated on the scene and declined to go to the hospital for further evaluation.

After conducting an investigation on the home, firefighters found a malfunctioning natural gas furnace in their condo unit that was credited with emitting the higher than usual CO levels. They shut off the furnace and ventilated the area until levels returned to normal.

The Prince George’s County Fire Department wants use this situation to remind the public that carbon monoxide is “The Silent Killer” – that is to say it’s colorless, odorless, and tasteless gas – and can only be detected with the proper monitoring equipment.

This hallway ceiling CO detector alerted to unhealthy levels of CO. (Credit: MEBRADY)