It’s cold enough that most of us have turned on furnaces or at least have space heaters in place. Three Rivers Public Health Department reminds us that gas and oil furnaces can produce a deadly, odorless gas called Carbon Monoxide. It can make people very sick and can kill. You should have your furnace inspected every year, clean furnace filters regularly, install CO detectors in your home and make sure they are working properly, and keep any flammable materials at least 3 feet away from furnaces and space heaters. If you suspect Carbon Monoxide poisoning, call 911 immediately.