Illinois officials are urging homeowners to be aware of potential carbon monoxide poisoning with homes shut up tight for winter.
Carbon monoxide is an odorless, tasteless and invisible gas that can be deadly when high levels are inhaled. It can be produced by faulty or poorly repaired appliances such as furnaces, water heaters and dryers. Dirty wood fireplaces, blocked chimneys and gas space heaters can also cause problems.
Illinois State Fire Marshal Larry Matkaitis says residents should check batteries on carbon monoxide detectors.
State law requires CO detectors within 15 feet of every room used for sleeping in a home or apartment.
Symptoms of carbon monoxide poisoning include headache, dizziness, weakness, nausea, vomiting, sleepiness and confusion.