Dangerous levels of carbon monoxide - a colorless and odorless gas - can be produced from improperly vented furnaces, plugged or cracked chimneys, water heaters, space heaters, fireplaces, stoves, and tail pipes. Any vehicle or appliance that burns fuel may emit carbon monoxide.

Hundreds of people die from carbon monoxide poisoning every year, and thousands of others suffer dizziness, severe headache, and nausea. The most common symptom of carbon monoxide poisoning is headache. However, symptoms may also include dizziness, chest pain, nausea, and vomiting. In severe cases, people can become increasingly irritable, agitated and confused, eventually becoming lethargic and lapsing into unconsciousness. Everyone is at risk, however, people with low red blood cell counts, heart or respiratory ailments as well as infants are at higher risk.

If you suspect carbon monoxide poisoning:

• Leave your home
• Call 911
• Get any victims to fresh air immediately
• Open windows
• Call your gas provider

• Install a carbon monoxide detector in your home and check it regularly to make sure the battery is working. NYC law requires owners to provide and install at least one approved carbon monoxide alarm within 15 feet of the primary entrance to each sleeping room.
  Learn more about NYC's carbon monoxide detector law 
• Make sure your heating system is kept clean and properly vented; have worn or defective parts replaced.
• Have your fireplace, chimney, and flue cleaned every year to remove soot deposits, leaves, etc.
• Kerosene heaters are dangerous and illegal in New York City.
• Don't heat your home with a gas stove or oven.
• Do not use any gas-powered appliance, such as a generator, indoors.
• Never use a charcoal grill or a hibachi indoors.
• Automobile exhaust contains carbon monoxide. Open your garage door before starting your car and do not leave the motor running in an enclosed area. Clear exhaust pipes before starting a car or truck after it snows.

NYC's carbon monoxide detector law (NYC Housing)
Carbon monoxide fact sheet (NYC Health)
Smoke and carbon monoxide alarms (FDNY)