Madison, WI — A home was briefly evacuated Tuesday morning after snow covered up an outside furnace vent and led to a carbon monoxide emergency on Madison’s south side.

A resident on the 2100 block of Pike Drive called 911 after two of her carbon monoxide detectors went off at around 8:45 a.m., according to an incident report.

The woman evacuated the unit and waited outside with her dog until the crew arrived. Firefighters went into the home with an air monitor and detected CO levels ranging from roughly 40 parts per million to 60 ppm.

The report said firefighters searched a nearby condo unit and also found residual CO readings. Officials determined the carbon monoxide buildup was due to an abundance of snow that covered a furnace vent outside the building.

The crew brought fresh air into the units in order to bring down CO levels. Madison Gas and Electric also assisted at the scene to check other units for carbon monoxide.

To prevent similar incidents in your own home, MFD reminded residents to make sure snow is not covering up any outside furnace vents.