Carbon monoxide (CO), produced when certain fuels burn, is a deadly gas that you cannot see or smell. You can inhale CO when you are not aware of its presence, resulting in sudden illness or death. Combustion fumes such as those made by cars, trucks, lanterns, stoves, gas ranges, charcoal grills, gasoline generators and heating systems contain CO. It often mixes with other odorless gases.

Carbon monoxide poisoning is the most common cause of poisoning in the United States; unintentional CO poisonings lead to roughly 500 deaths and 15,000 emergency room visits annually. Carbon monoxide poisoning can occur any time of the year.

When breathed, carbon monoxide displaces oxygen in the blood, depriving the heart, brain and other vital organs of that element. Large amounts of CO can overwhelm you in minutes without warning, causing you to lose consciousness.

Signs and symptoms of CO poisoning include headache, dizziness, weakness, confusion, memory loss, nausea, vomiting, trouble breathing, chest pain and an irregular or fast heart rate. One can easily mistake mild carbon monoxide poisoning for the flu. Symptoms vary widely from person to person.

CO poisoning may occur sooner in young children, elderly people, people with heart or lung disease, people at high altitudes or those with already elevated CO blood levels, such as smokers. Carbon monoxide poisoning also poses a dangerous risk to fetuses.

If caught in time, CO poisoning can be reversed. For those who survive, recovery is slow. How well a person responds to treatment depends on the amount and length of exposure to CO. Even if you recover, acute CO poisoning may result in permanent damage to parts of your body that require a lot of oxygen, such as the heart and brain. Significant reproductive risk is also linked to carbon monoxide poisoning.

If you suspect CO poisoning, promptly take the following actions: Move the victim to fresh air in an open area. Call 911 or another local emergency number if you are outside the United States. Administer 100 percent oxygen using a tight-fitting oxygen mask if the victim is breathing. Administer cardiopulmonary resuscitation if the victim has stopped breathing.

Carbon monoxide treatment aims at replacing the carbon monoxide in your blood as quickly as possible. In the hospital, you may breathe pure high-flow oxygen through a mask placed over your nose and mouth. This helps transport oxygen to your organs and tissues. If you cannot breathe on your own, a ventilator may do the breathing for you. In some cases, hyperbaric oxygen therapy is recommended.

Simple precautions can help prevent carbon monoxide poisoning. Invest in carbon monoxide detectors. Check your batteries every time you check your smoke detector batteries, at least twice a year. If the alarm sounds, leave your house immediately and call the fire department. Take a plug-in CO detector with you on vacation.

Never run your car in a closed garage. Remove snow or other debris from the tailpipe before using the car. Never use a gas stove or gas oven to heat your home. Use portable gas camp stoves or generators only outdoors away from the house. Keep your fireplace and gas appliances in good repair. Make sure your gas appliances are properly vented. Clean your fireplace chimney and flue every year. Ask your utility company about yearly checkups on all gas appliances, including your furnace.

CO poisoning can occur on boats as well. Make sure your boat has a working CO detector. Traveling at low speeds or idling in the water can cause CO to build up in the boat’s cabin, cockpit, bridge, aft deck or an open area. Dock, beach or anchor at least 20 feet from the nearest boat running a generator or engine. Exhaust from a nearby vessel can send CO into the cabin and cockpit of your boat.

If carbon monoxide poisoning has occurred in your home, it is critical to locate and repair the source of the CO before your return. Your local fire department or utility company can help. For more information, visit www.cdc.gov.

DETECTION AND PREVENTION

• Have heating systems, water heaters and any other gas-, oil- or coal-burning appliances serviced by a qualified technician every year.

• Do not use a generator, charcoal grill or any other gas- or coal-burning device inside your home, garage or outside near a window.

• Do not leave your car running in an enclosed space.

• Place additional CO detectors near any major gas-burning appliance, such as a furnace or water heater.

The content of this article is for informational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified health care provider with any questions you may have regarding a medical condition.