PHILADELPHIA (WPVI) -- There are more than a million house fires in the US every year and while flames are dangerous, more people are injured and killed by smoke inhalation.
Even a short period of time with limited oxygen can cause permanent damage to the nervous system. And in modern homes, the smoke can have a lethal mix of toxic products.
"Mostly carbon monoxide, but actually also cyanide. In homes that have a lot of synthetic material, rubbers, plastic, foam - when that burns, that can also cause some cyanide poisoning," said Dr. Baruch Fertel.
Smokers are more sensitive to carbon monoxide, because their airways are already damaged by tobacco.
It's never safe to enter a burning home - even if you think you're away from the flames, you can be overcome very quickly by fumes.
Of course, everyone should check to make sure your home has working smoke detectors and carbon monoxide detectors.
Smoke kills more than flames during a house fire