ARVADA, Colo. (CBS4)– Firefighters in Arvada say a new tool saved a family that was inside a home filled with carbon monoxide.

The fire crews in Arvada carried the carbon monoxide detectors with them into the home which warned firefighters of the danger when they walked through the door.

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“If this goes off, there’s a visual and audible alarm that will start flashing red and gives us tones,” said Arvada Fire Department spokesman Mike Roluti. “This will alert us if there’s any carbon monoxide in the house

The alarms have sounded several times in recent weeks including the visit firefighters made to Arvada for an unknown medical call. Three people were rushed to the hospital.

It gives fire crews an advance warning of what may be a potentially deadly situation.

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“When we got there the alarm went off as soon as we got inside the door,” said Arvada Fire Dept. spokesman Scott Pribble.

Two weeks ago a woman and her dog were treated for high levels of carbon monoxide in their home.

“In the high levels we had in that home, over 800 ppm, that would have affected our firefighters as well,” said Pribble.

It is a law in Colorado to have a carbon monoxide monitor in every level of your home.

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Those monitors also expire after five years of use so it’s important to make sure they are up to date.