With winter weather approaching, so comes the risk for carbon monoxide poisoning.

According to the Minnesota Department of Commerce, each year about 500 people die throughout the nation from unintentional exposure to carbon monoxide. More than 20,000 people visit the emergency room, and more than 4,000 are hospitalized, according to the Centers for Disease Control and Prevention.

Carbon monoxide can build up dangerous concentrations indoors when fuel-burning devices are not properly vented, operated or maintained. Those devices include everything from furnaces, water heaters and gas or kerosene space heaters to charcoal or gas grills, fireplaces, wood stoves and motor vehicles.

Carbon monoxide poisoning is most common in the winter months when heating systems are used and car engines are sometimes left running in garages. Carbon monoxide can also form in the cabin areas of boats or ice houses with heating equipment.

Such was the case when an Austin man died in January inside an ice house on Clear Lake in Waseca County. The Ramsey County Medical Examiner’s Office determined the man’s cause of death was accidental and that he died from carbon monoxide poisoning.

The Minnesota Department of Health offers three tips to prevent carbon monoxide poisoning:

• Properly vent and maintain fuel-burning appliances.

All fuel-burning appliances should be vented to the outside and should be checked by a heating contractor annually. Don’t use an appliance inside that is intended for the outdoors. Do not idle cars in garages for any length of time. High levels of carbon monoxide can accumulate even in garages with the doors open.

• Know the symptoms of carbon monoxide poisoning.

Symptoms of carbon monoxide exposure are similar to flu-like symptoms. First signs often include a mild headache and breathlessness with moderate exercise.

Continued exposure can lead to more severe headaches, dizziness, fatigue and nausea.

If you have carbon monoxide poisoning, you may feel better when you are away from home, will be sick at the same time as others in the house and will not have a fever or body aches that come with the flu.

• Install and maintain carbon monoxide alarms in your home.

State law requires every home to have at least one operational carbon monoxide alarm within 10 feet of every room used for sleeping.