BOSTON -- Carbon monoxide poisoning kills hundreds and sends thousands to the hospital every year. The fumes are tasteless and odorless, which is why states like Massachusetts have passed laws requiring carbon monoxide detectors in homes.

NewsCenter 5's Heather Unruh reported Tuesday on how you can protect your family.

As we begin to turn on the heat and fire up the fireplace, fire officials are reminding homeowners of the dangers of carbon monoxide poisoning.

"It's commonly known as the silent killer. Carbon monoxide is colorless, it's odorless and tasteless,” said Massachusetts State Fire Marshal Stephen Coan.

“It's a problem in homes that has fossil burning fuel options; gas, oil, propane, coal, or wood,” said Needham Fire Chief Paul Buckley.

Carbon monoxide fumes can come from many areas in your home, such as a furnace, a stove, or a fireplace. Nearly three years ago a snow-covered heating vent backed up poisonous gases in a Plymouth home. Seven-year-old Nicole Garofalo died. Her tragic death prompted a Massachusetts law requiring carbon monoxide alarms on every level of most houses. Where you place them is critical.

“There must be an alarm within 10 feet of an entrance to each bedroom, and in floors where there are not bedrooms but living rooms, kitchens, dens, other areas of habitation,” Coan said.

“If you have a playroom in your basement you need one,” said Buckley.

Without a carbon monoxide alarm, which costs about $30, experts say carbon monoxide is a poisonous gas that gives very little warning.

“They can get nauseated, they can get headaches, and it can often be confused with the flu,” said Dr. Aaron Waxman, of Massachusetts General Hospital.

Coan said the carbon monoxide alarm is key to clearing up the confusion.

“Its activation tells us, no we don’t have the flu, that there is something else going on. That it is carbon monoxide and it's time to get,” he said.