MADISON, Wis. -- The Madison Fire Department has issued a word of caution for those seeking to keep warm in the face of the upcoming cold snap.

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With energy costs as high as they are, some people might be looking to space heaters ways to keep warm against the winter chill. However, fire officials warn against making a common mistake -- cozying up to a fuel-burning heater indoors.

"For the most part, if it's going inside the house, we try to push for electrical heaters," said Matt Grace, an assistant manager at Home Depot. "You don't have to worry about carbon monoxide, or any of the other side effects."

SPACE HEATER REMINDERS Allow 3 feet of space Check for seals of approval Follow instructions Never leave heater unattended

Grace said that although they also carry kerosene fuel heaters and others, those types are for higher ventilation areas -- like the outdoors.

According to Grace, electric heaters also tend to be safer. Lori Wirth, of the Madison Fire Department, agrees.

"We discourage (the) use of any kind of fossil fuels inside the home. That really isn't where they're supposed to be," said Wirth.

Wirth said using a fuel heater indoors can easily lead to carbon monoxide poisoning or fires.

Two weeks ago, fuel spilt out of a kerosene heater and started a fire in Philadelphia that claimed the lives of seven people, WISC-TV reported.

Still, the Home Depot on Madison's West Side is selling plenty of both. Wirth said it is important thing to follow the manufacturer's instructions.

"There are some things that are perfectly fine for ourtdoor use but not indoor use," said Wirth. "You want to make that distinction, read those instructions and make sure you're using them according to how the manufacturer intended."

Wirth said last-ditch efforts to keep warm during a cold snap can become very dangerous.

"Some of the extremes that we've seen are people who try to heat their homes with ovens, with stoves or even -- in some cases -- bringing charcoal grills into the home," Wirth said. "All of these are things that we greatly discourage. They are dangerous."

The Madison Fire Department issued the following tips to stay safe while staying warm with space heaters this winter:

1. Check for seals of approval on any heater you would buy.
2. Follow the manufacturer's instruction for use.
3. Leave 3 feet around heaters to prevent fires.
4. Turn heaters off before leaving a room.

Fire officials also warn about warming cars or using fuel space heaters inside garages, as carbon monoxide gasses can easily seep into homes -- even if the door is open.