If you use oil or natural gas for heating and cooking -- or even burn wood in a wood stove -- you may be inviting a silent killer into your home.

It's carbon monoxide gas, and hundreds die from it every year.

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You can't smell it, but a carbon monoxide detector can.

David DeSavino smelled gas coming from a faulty water heater and it scared him to death.

"I have two young children and a little dog and a wife and I have to make sure they're protected," he said.

So he bought two carbon monoxide detectors for a poisonous gas that, unlike treated natural gas, has no noticeable odor. When the devices detect carbon monoxide fumes, they let off an ear-piercing squeal.

"It's very important to have a carbon monoxide detector in your home. It's recommended that you have one on every floor of the house and especially in the bedrooms," said Ray LaMantia, an insurance agent.

The Centers for Disease Control in Atlanta says between three and five thousand Americans are rushed to hospitals every year, suffering from carbon monoxide poisoning. Hundreds more die from it.

The fumes can come from defective stoves, furnaces and cars left running in garages.

It's important to place the detectors near bedrooms, especially upstairs, or any place a gas leak can occur.

It's also a good idea to have all appliances installed by professionals, and never use a stove or oven to heat your home.

"If the alarm goes off on your carbon monoxide detector, you should go out and get some fresh air, that's the very first thing you should do."

The next thing to do is call 911 for help.

And don't forget to test your alarm at least a couple of times a year.

Remember: these devices don't replace your home's smoke detectors. You still need those, as well.