Carbon monoxide (CO) is an odorless, tasteless and colorless gas that’s very dangerous. It’s produced when fuels such as gasoline, kerosene, wood, oil, charcoal and natural gas are burned. When inhaled, CO reduces the amount of oxygen that travels in the blood to important organs, causing carbon monoxide poisoning – which can be harmful and even fatal.

If you think you have carbon monoxide poisoning, or think you’ve been exposed to carbon monoxide, it’s important that you go outside to fresh air immediately and seek medical attention by calling 911 or going to the nearest emergency room.

Below, we’ll explain the signs, symptoms and side effects of carbon monoxide poisoning. We’ll also go over the causes of carbon monoxide in your home, how you can detect it and treatment if you think you have carbon monoxide poisoning.

Signs and symptoms of carbon monoxide poisoning

According to the Centers for Disease Control and Prevention (CDC), more than 400 people in the U.S. die from unintentional CO poisoning each year. And more than 100,000 end up in the emergency room due to accidental carbon monoxide poisoning.

Milder cases of carbon monoxide poisoning can look like the flu or other illnesses, so it can be difficult to know what’s causing your symptoms. If you suspect CO poisoning, even minor symptoms are very serious and should be addressed immediately by going outside and calling 911.

Early signs and symptoms of carbon monoxide poisoning

  • Mild or moderate headache
  • Shortness of breath
  • Dizziness
  • Weakness
  • Nausea and vomiting
  • Rapid heartbeat
  • Sore throat

Signs and symptoms of moderate cases of carbon monoxide poisoning

  • Severe headache
  • Chest pain
  • Seizures
  • Loss of coordination (ataxia)

Signs and symptoms of severe carbon monoxide poisoning

  • Loss of consciousness
  • Respiratory failure
  • Coma

If you think you’re experiencing any symptoms of carbon monoxide poisoning, call 911 or go to the nearest hospital emergency room.

How long does it take to get carbon monoxide poisoning?

The amount of time it takes for CO to affect you depends on the amount of the gas you’re exposed to. If you’re exposed to small amounts of carbon monoxide over a period of time, it can take a few weeks to feel the effects. If you’re exposed to a large amount, it can be deadly within minutes of exposure.

Risk factors for carbon monoxide poisoning

Some people are more at risk of carbon monoxide poisoning depending on certain factors, including:

  • Adults over the age of 65
  • Infants
  • Developing fetuses
  • People who use smoke tobacco products
  • People who live in high altitude
  • People who have health issues like heart disease, respiratory issues or anemia
  • People and pets who are small in size

People with certain careers are also more likely to have exposure to CO – like those that work in warehouses or refineries – due to the presence of fires or combustion engines. These can include:

  • Firefighters
  • Mechanics
  • Welders
  • Drivers

Possible causes of carbon monoxide in your home

While carbon monoxide can be found anywhere fuel is burned, it most commonly occurs in your home, especially if you have an attached garage or appliances that burn fuel. Common sources of carbon monoxide can include:

  • Clothes dryers
  • Fireplaces, both gas and wood burning
  • Furnaces and boilers
  • Grills
  • Generators
  • Motor vehicles
  • Power tools and lawn equipment
  • Tobacco smoke
  • Water heaters
  • Wood stoves

Carbon monoxide concerns in Minnesota and Wisconsin

If you live in a climate that can get very cold like Minnesota or Wisconsin, you may be more at risk of carbon monoxide poisoning as you may be around sources of carbon monoxide for longer periods of time. For example:

  • Ice fishing and ice houses – Ice houses are often heated with propane gas. Without proper ventilation and improper use of propane, gasoline and charcoal burning devices inside and directly outside your ice house, carbon monoxide can build up quickly.
  • Cabin heaters – A lot of cabins in Minnesota and Wisconsin are in more remote areas and use gasoline and charcoal for fuel in generators, grills, camp stoves and other appliances, meaning there may be more risk for carbon monoxide exposure.
  • Heating while camping – Using space heaters, grills and generators that are fueled with propane, gasoline or kerosene are common while camping, in both tents and trailers. If these appliances aren’t used and vented properly, carbon monoxide can reach dangerous levels.
  • Idling in the garage and workshop generators – Generators and cars are designed to operate outside and send their exhaust into the atmosphere. It’s extremely dangerous to use an electric generator inside a workshop or idle your car inside the garage as that produces carbon monoxide.
  • Leaving a car running if stuck in snow – Cars have tailpipes that expel exhaust fumes. When your tailpipe is blocked or clogged by anything, like snow, the exhaust fumes will have nowhere to go but into your car, exposing you to carbon monoxide.
  • Warmer weather and carbon monoxide exposure – While carbon monoxide poisoning is more common in colder months, there’s still the possibility of carbon monoxide exposure and poisoning in warmer weather. Camp stoves, nonelectric heaters, barbecue grills and boat motors are all potential sources of carbon monoxide.

The best way to detect carbon monoxide is by using carbon monoxide detectors. CO detectors are inexpensive and can be found at your local hardware store or home improvement store. CO detectors work by detecting the concentration of CO in the air.

You can also look for other signs around your house that there may be a carbon monoxide leak. These include:

  • A pilot light on your gas fireplace or gas stove keeps going out
  • Heavy condensation on windows near a leaking appliance
  • Brownish-yellow or sooty looking stains around a leaking appliance
  • Air that smells like something that is burning or overheating
  • Smoke, fumes, soot or a back draft in your fireplace, chimney or other equipment that burns fuel
  • Lack of upward draft in your chimney flue
  • Pilot light in your stove that is yellow instead of the normal blue

How to prevent carbon monoxide poisoning

The most reliable form of prevention is with carbon monoxide detectors on each level of your home, and outside of each sleeping area. Routine maintenance is important too.

If your CO detector is hardwired, test it every year. If you have a battery-powered detector that plugs into the wall, test it when you change your clocks in the spring and the fall, and change the battery every year.

At the beginning of the heating season, it's also important to do a yearly inspection of any fuel-burning appliances in your home. This includes:

  • Chimneys and flues (check for cracking or blockages)
  • Fireplaces
  • Gas ranges and dryers
  • Gas water heaters
  • Kerosene or gas space heaters
  • Oil or gas furnaces
  • Wood stoves

Make sure to take precautions when using any fuel-burning appliances. Buy gas appliances that have a seal from a national testing agency and choose appliances that can be vented outside. Carefully follow the instructions for fuel-burning appliances and call an expert if you think your appliances aren’t working properly. If you’re using a gas space heater, make sure you’re using the right fuel, and never sleep in a room that has an unvented kerosene or gas space heater.

Easy steps you can take to lower your risk of carbon monoxide poisoning

When it comes to carbon monoxide, even the smallest preventive step can help you lower your risk of CO poisoning. The most important thing you can do is to have functioning and well-maintained carbon monoxide detectors in both your home and garage. Other important steps you can take:

  • When at home or camping, only use a gas or charcoal grill outside, avoid using fuel-burning appliances inside your home, cabin or garage; and don’t use them outside near any windows.
  • Only idle or warm up your car, or work on your car, outside of the garage to avoid carbon monoxide from getting into your home.
  • Only use gas-powered engines, like those for power washers, generators and chainsaws, in outdoor spaces.
  • For ice houses, make sure snow isn’t blocking your vents and that propane tanks remain outside of your ice house at all times. You can have a small portable heater inside your shelter, but it should have no more than a 1-lb. cylinder of propane. You should also never use gasoline and charcoal burning devices in or near the windows of your ice house.
  • Any fuel-burning devices in your cabin, like propane heaters, should be properly installed, vented and maintained. You should also never use gasoline and charcoal burning devices inside your cabin, garage, basement or near a window.
  • Don’t sleep in a tent or a trailer with a gas- or kerosene-burning space heater that’s not properly installed, vented and maintained. Plus, avoid cooking with a gas grill, charcoal grill or camp stove inside a trailer or a tent – even with windows and doors open.
  • If your car is stuck in the snow in a safe area without a lot of traffic, get out of your car and check to make sure your tailpipe is clear. If you’re in an area where it’s not safe to get out and check, turn off your engine, stay in your car and call 911 for help.
  • If you’re on a boat, stay away from the exhaust area in the back of the boat, be aware of exhaust from neighboring boats and install a carbon monoxide detector in the cabin of your boat, if it has one.

Testing and treatment for carbon monoxide poisoning

If you suspect carbon monoxide poisoning, the first step is to get away from the source of the carbon monoxide as soon as safely possible. Then seek medical attention right away – call 911 or go to the nearest emergency room.

Your doctor will ask you about your exposure to carbon monoxide, including where you were exposed and for how long. They’ll take a blood sample to test it for CO and use a pulse oximeter to check your heart rate and oxygen levels.

Carbon monoxide poisoning is treated by giving you pure oxygen to breathe. This will help offset the CO buildup in your body. Mild CO poisoning symptoms may go away by simply moving outside away from the source, or by using an oxygen mask.

It can take up to 24 hours for CO to leave your body, so you may experience symptoms during that time, and depending on the severity of your exposure, you may also experience symptoms for a longer amount of time.

Long-term effects of carbon monoxide poisoning

If you experience CO poisoning, you may have lingering effects that can be long-term, and it can take a while to recover. Some symptoms may show up right away while some are slower to appear, including:

  • Cognitive issues, such as difficulty concentrating and problems with memory
  • Changes to mental and psychological functions, like depression and irritability
  • Problems with brain, nerve and spinal cord function

Prevention is key when it comes to carbon monoxide

The best way you can prevent carbon monoxide poisoning is by using carbon monoxide detectors. If your carbon monoxide detector goes off, don’t try to find the source of the gas. Go outside and seek medical attention immediately.

If you have severe symptoms, call 911 or go to the nearest hospital emergency room. Avoid going back into your house (or area you suspect you were exposed to carbon monoxide) until you’re cleared to do so.