Carbon monoxide is known as the ‘silent killer’ for a reason. Here is what to know.

Carbon monoxide, an odorless and colorless gas known as a “silent killer,” is suspected in the death earlier this week of a man living in Southwest Philadelphia.

Police and firefighters found the man dead inside a building that was evacuated because of high levels of carbon monoxide Tuesday afternoon in Southwest Philadelphia.

» READ MORE: Man dead in suspected carbon monoxide incident in Southwest Philly

Carbon monoxide poisoning kills about 400 Americans a year and sickens about 50,000 more, according to the Centers for Diseases Control and Prevention. About a third occur during the winter, when people are more likely to use carbon monoxide-producing gas furnaces and heaters, and portable generators when storms cause power outages.

Here is what you need to know to prevent carbon monoxide poisoning:

Carbon monoxide, or CO, is produced when fossil fuels, wood, or anything that contains carbon is burned. Potential household dangers for producing carbon monoxide include heating systems, portable generators, charcoal grills, and cars, according to the CDC.

Unlike its chemical cousin, carbon dioxide, carbon monoxide is not a greenhouse gas that contributes to global warming. Instead, when people breath it in, carbon monoxide binds to the part of the red blood cell that transports oxygen in the body. This means that vital organs, especially the heart and brain, do not receive the oxygen that they need to function and survive.

“It’s like you are in an environment without oxygen,” said Fred Henretig, senior toxicologist at the Poison Control Center at the Children’s Hospital of Philadelphia.

Carbon monoxide poisoning can range from mild to severe. People with modestly elevated carbon monoxide levels in their blood might experience flu-like symptoms, nausea, and vomiting, Henretig said.

People with high carbon monoxide blood levels can suffer stroke-like symptoms and lose consciousness.

In the most extreme cases, when the concentration of carbon monoxide is very high, people may rapidly black out and experience seizures and comas, leading to death.

Depending on the levels of carbon monoxide, symptoms can develop within minutes to hours.

Young children and older adults are the most sensitive to the effects of carbon monoxide.

People with mild carbon monoxide poisoning generally recover after treatment with high concentration of oxygen delivered under medical observation for a few hours.

These patients may also require physical examination to ensure that there was no damage to the heart, Henretig said.

More severe cases might require a special form of oxygen treatment performed in a hyperbaric chamber.

Every household should have working carbon monoxide detectors. People can also avoid situations that produce carbon monoxide in the first place by following CHOP’s recommendations for safeguarding homes:

The CDC also urges never running a vehicle in a garage that is attached to a house, even if the garage door is open.

If you suspect carbon monoxide poisoning, leave the building as soon as possible and call 911.

» READ MORE: Carbon monoxide leak at Allentown day care center injures 25 children

If you rent and have concerns about your unit’s carbon monoxide detectors, call your landlord and ask that everything be checked and in working order.

“Your landlord is responsible for having a working carbon monoxide detector in Philadelphia,” said Jenna Collins, housing attorney at Community Legal Services, a legal aid group in Philadelphia. She noted that landlords are also required to provide working smoke detectors.