The first official day of winter brings with it a warning from officials. If you have a fireplace or wood-burning stove, make sure you clean it well and clean it often.

"When wood burns…you get creosote build-up, which is a black substance that builds up on the walls of the fire places and if that's heated to a certain extent, it will actually catch on fire itself. And that's how you have a chimney fire," explains Michael Farley, who installs fireplaces in Michigan. "If you treat them right and you're careful with them, they're perfectly safe but it is a fire in your house."

An 85-year-old South Bend woman learned that destructive lesson Sunday night when her wood-burning stove started a fire.

"When they went into the bedroom area to check the stove, they opened the door and that's when they found all the flames and it was really too far gone by then," says Chief Terry Korpal, Southwest Central Fire Territory, about the fire in the 24000 block of Ardmore Trail. "You have to really inspect fireplaces on a regular basis. I think the cleaning is over-looked. It sort of a pain in the neck to do and I don't think you find a lot of people interested in doing that."

"Maintenance is a big part of that," says Herbert Herendeen, Hearth and Home Design Center in South Bend. "It's like not checking the tire pressure in a car before you leave for a trip or something silly like that. Well, you should clean the chimney every year prior to its use in the fall."

You can buy the supplies to clean your own chimney, but officials urge you to make sure you know what you're doing. They say people don't realize how complex the piping can be and don't clean properly or sufficiently.

Professional, licensed chimney sweepers say while their services are more expensive than doing it yourself, they have the proper tools and skills.

It takes heat, fuel and oxygen to start a fire, and you have all those in your chimney. With just the right combination, things could go very wrong.

Fire officials respond to several wood-burning stove fires every winter. The National Fire Prevention Association says based on a study conducted in 2005, two-thirds of chimney fires are caused because they're not properly cleaned.