Local authorities are encouraging residents to be wary of carbon monoxide buildup in their homes following an incident caused by the recent wintry weather. At approximately 8:03 a.m. Saturday, the Storm Lake Fire Department was dispatched the 100 block of Mckenna Drive in response to a carbon monoxide detector sounding in a residence. Upon arrival, firefighters identified elevated levels of the toxic gas throughout the home and identified the cause as furnace intake and exhaust pipes blocked by snow. With assistance from the Storm Lake Police Department and Alliant Energy, crews were able to clear the blockage and vent the gas without injury to the occupants. Extended exposure to the odorless gas can cause headaches, dizziness, vomiting and even death. Residents are being reminded to check the batteries in their carbon monoxide detectors or install one if do not have any. Authorities encourage people to ensure the ducts connected to natural gas furnaces and water heaters are always clear, especially during times of heavy snowfall or drifting.