NASHVILLE, Tenn. (WKRN) — Assumption can be a “deadly practice,” according to the Monroe Carell Jr. Children’s Hospital at Vanderbilt.

Every year, more than 400 people in the United States die from carbon monoxide poisoning, and thousands are sickened by the colorless, tasteless and odorless gas known as the “silent killer.”

Carbon monoxide is present in the air we breathe day-to-day, but when unsafe levels of the gas build up, Stacey Pecenka, MPH, Trauma Injury Prevention Program Manager at Monroe Carell said it can lead to carbon monoxide poisoning.

An alarm is the only way to know if there are dangerous levels of carbon monoxide in the air.

“Don’t assume that there is a carbon monoxide detector wherever you are,” Pecenka said. “Don’t assume your schools have one, or the home you are buying has one installed. Definitely ask about placement and if they are in working order.”

Pecenka said it is also important to note that smoke alarms and carbon monoxide detectors are not the same thing.

Any appliance or heat source that uses combustible sources of fuel like propane, coal, gasoline and natural gas can generate carbon monoxide. Some common sources are room heaters, furnaces, charcoal grills, cooking ranges, water heaters, cars and portable generators.

Carbon monoxide can be safely vented most of the time, but misusing or not maintaining the sources can lead to unsafe levels in the air. Therefore, Pecenka said it is important for “everyone” to have a carbon monoxide detector in their home or place of business.

“Even if you don’t use gas appliances or heating sources, you still need a detector,” she said. “When temperatures dip, people use alternative heat sources that could be damaging. There are many ways that carbon monoxide can enter a home or place of business, especially during the winter months.”

Children are at higher risk for carbon monoxide poisoning and become sicker much quicker than adults because their bodies process the gas differently.

Signs of poisoning include headache, dizziness, sleepiness and nausea. If symptoms affect more than one person, a carbon monoxide leak or exposure should be considered. Those affected should immediately get fresh air.

The Monroe Carell Jr. Children’s Hospital also recommends testing alarms monthly, putting a detector on every level or your home near sleeping areas and teaching children how to respond if an alarm sounds. A beeping alarm should never be ignored.