By Mia Stephens 

Every year, hundreds of lives are claimed by a silent, but easily preventable killer – carbon monoxide poisoning.  

Early signs of this poisonous gas are easily missed due to lack of odor, taste, and appearance. In 2024, the Virginia Poison Center at VCU Health had 182 human exposures calls related to carbon monoxide exposure.

“We often see more of these poisonings occur during winter months and natural disasters when people may use alternate methods of heating homes or obtaining electricity. Kerosene heaters, barbecue grills, or gasoline powered generators can all lead to carbon monoxide poisoning if they are used indoors or in areas without adequate fresh air flow,” according to John Downs, M.D., M.P.H., director of the Virginia Poison Center at VCU Health. However, carbon monoxide poisoning can occur at any time. 

Depending on the amount of exposure, the gas can build up to a dangerous level causing mild symptoms or even death in some cases. According to the Centers for Disease and Control Prevention, around 400 Americans die from unintentional carbon monoxide poisoning not linked to fires each year. More than 100,000 people visit the emergency room and around 14,000 are hospitalized due to their symptoms as well. 

VCU Health spoke with Downs about signs and symptoms of carbon monoxide poisoning and best practices for protecting your home.  

What is carbon monoxide poisoning?

Carbon monoxide poisoning occurs when someone breathes in a dangerous amount of gas from a source.  

Carbon monoxide is known as a colorless, odorless, tasteless and poisonous gas that has no warning signs. It is produced from a fuel burning appliance or device.  In most cases, poisonings occur when carbon monoxide is released indoors or in poorly ventilated spaces.  

Sources that might produce carbon monoxide include:

• Fireplace
• Wood Stoves
• Furnaces that use gases or oil 
• Gas stoves or ovens 
• Gas water heaters 
• Kerosene heaters 
• Car engines 
• Generators  

What are the symptoms of carbon monoxide poisoning?

Common symptoms include headaches, dizziness, nausea, weakness, and fast heartbeat.  

While severe cases tend to experience vomiting, coma, confusion, loss of consciousness, a heart attack, and even death.  

Typically, the severity of symptoms is linked to the amount of gas exposure.  

“It’s really a combination and how high the carbon monoxide concentration is in the air, and the amount of time that an individual spends in that area,” Downs said. “Fortunately, modern carbon monoxide detectors are constantly measuring for carbon monoxide and will alarm not only when the air concentration rises quickly, but also when lower air concentrations have been present for too long to be safe.” 

In some instances, it takes up to 2 hours for symptoms to occur or as little as 5 minutes. Populations who pose a greater risk of getting sick from carbon monoxide are:

• Smaller children, especially with asthma
• People who smoke tobacco regularly
• People who are pregnant; might pose a risk of miscarriage and health problems to their fetus
• Older adults
• People with chronic illnesses such as heart disease, anemia, or breathing problems.  

Are pets affected the same way people are?

No matter the size of your pet, they are still susceptible to carbon monoxide poisoning. Based on the structure of their respiratory system, birds are more sensitive to carbon monoxide poisoning than other animals. 

Pets present similar symptoms to humans but differ in some ways including depression, seizures, cardiac arrhythmias, acute respiratory disease, and possibly permanent deafness and blindness.  

Animals who are able to recover from carbon monoxide poisoning should be carefully monitored for up to a week or longer for worsen symptoms or neurological signs. 

What should I do if I notice someone is experiencing carbon monoxide poisoning symptoms?

It is important, if possible, to move to an area with fresh air and call the Virginia Poison Center right away for medical assistance.  

“We will most likely direct those affected to a fresh air source, discuss what concerning signs and symptoms to look for, and what sources might be leading to carbon monoxide exposure,” Downs said. “We may also suggest fire department involvement to assess the living space for carbon monoxide.” 

However, sometimes, but not always, people will need to go to the hospital for oxygen treatment. If someone has collapsed, has difficulty breathing or is unconscious, immediately call 911.  

“These could be signs of severe carbon monoxide poisoning, and immediate medical attention is needed to potentially save a life,” Downs said. “If you suspect carbon monoxide poisoning in yourself or a family member, and immediate life-threatening effects aren’t present, call the Virginia Poison Center.”  

For pets, they should be taken to the nearest emergency veterinarian hospital as soon as possible to be evaluated. 

How can I prevent carbon monoxide poisoning from happening in my home?

The key to avoiding carbon monoxide exposure is prevention. It is recommended that every home has dual smoke and carbon monoxide detectors installed and regularly maintained.

“Check the manufacturer’s instructions for specifics, but most detectors will need to be changed every 5-10 years,” Downs said. “It is a good idea to check and change batteries in these devices about every 6 months to ensure they are working correctly. If your dwelling uses wood or gas for heating or cooking, ensure that these systems are professionally inspected and maintained at least yearly.” 

For homes that use wood or gas for heating or cooking, it is important to ensure that these systems are professionally inspected and maintained yearly.  

Here are several tips you can implement to keep you safe, especially during the winter months:

• Install carbon monoxide detectors in your home. Ideally, you should have one on each level of your home near bedrooms and furnaces.
• For smoke detectors, be sure to test and replace the batteries regularly.
• Have your heating system and chimney professionally checked each year. 
• Never use your oven or stovetop to heat the home.
• Never run a car in a closed garage, even for a few minutes.
• Do not use charcoal or gas grills in the house, garage, or any other enclosed space.
• If you use a generator, make sure it’s outside more than 20 feet away from air intake vents, windows, and doors leading to the home.