Overland Park ? A northeast Kansas fire department has responded to two carbon monoxide poisoning calls since a massive snowstorm hit the area.

The Overland Park Fire Department said in a release Wednesday it had two reports of carbon monoxide poisoning in the previous 24 hours — and the problem may have resulted from snow covering the exhaust vents of high-efficiency furnaces.

The Overland Park department says the exhaust from high-efficiency furnaces emits low heat and is often vented through plastic piping on the side of a home. If the vents are blocked by snow, carbon monoxide can build up in the home.

The department urges residents to check outside vents.