State Fire Marshal William Swope is warning Kentuckians to beware of carbon monoxide buildup now that cool temperatures are forcing them to heat their homes and cars again.
Swope calls the odorless, colorless gas the "silent killer." It's produced by fuels like natural gas, propane, oil, wood, coal and gasoline.
In particular, Swope said people need to understand that vehicles and generators left running in attached garages can produce dangerous levels of carbon monoxide.
Symptoms of overexposure include shortness of breath, nausea, dizziness, lightheadedness or headaches.
Swope also warned that high levels of carbon monoxide can be fatal within minutes.