Carbon Monoxide (CO) is a colorless, odorless gas created when a fuel such as natural gas, propane, gasoline or wood is burned. Since you can’t see or smell CO, it is possible for dangerous concentrations of CO to build up indoors and cause illness before you realize you are being poisoned.

The first signs of CO poisoning include head-ache, dizziness, fatigue, nausea, and breathlessness with mild exercise. Since these symptoms are similar to those of viral illness, many people ignore these early signs which can allow the poisoning to get worse. CO poisoning symptoms can progress to confusion and irritability, loss of coordination, unconsciousness and death when exposed at very high levels.

Some signs that initial symptoms are from CO poisoning and not a viral illness include: you feel better when you are away from home; symptoms appear or get worse when using fuel-burning equipment; everyone in the household has symptoms at the same time; and no symptoms such as fever, body aches or swollen lymph nodes are present.

The Minnesota Department of Health (MDH) notes that common sources of potential CO in the home include: furnaces and boilers, clothes dryers (gas), water heaters, fireplaces, gas stoves, cars in attached garages, and generators. Properly maintaining fuel burning appliances and venting them to outside air is key to preventing CO poisoning in the home.

Under Minnesota law, every home is required to have at least one operating CO alarm within 10 feet of every room used for sleeping. Most CO alarms need to be replaced every 5-7 years, check the owner’s manual to see the recommended replacement schedule. If the CO alarm sounds, take it seriously. If any household members are feeling symptoms of CO poisoning, immediately leave the home and call your local fire department. If everyone is feeling fine, call your local gas utility company or a qualified technician to help identify the cause of the problem and make repairs. Do not re-enter the home until it is safe.

Common recreation activities in Minnesota such as boating, camping, and ice fishing can also lead to unintentional CO poisoning. Boaters should be aware of where the boat motor exhausts and should tow passengers at least 20 feet from this area. MDH notes that boats with a cabin are required to have CO alarms. When ice fishing, regularly inspect any heating equipment in use, keep a window slightly cracked for ventilation, and consider installing a battery powered CO alarm in the ice house. When camping, never use camp stoves, grills or fuel burning lanterns inside a tent, RV or cabin.

The Centers for Disease Control and Prevention (CDC), estimates that approximately 400 people die from unintentional CO exposure in the United States each year, including an average of 14 people each year in Minnesota. The CDC reports another 307 people visit the emergency room each year for treatment of symptoms related to unintentional CO exposure. Keep your household safe from this “silent killer” by installing CO alarms and maintaining fuel burning appliances.