MISSISSIPPI STATE -- Alternative heat sources used during extended power outages in the winter months can have deadly consequences without proper planning and supervision.

Herb Willcutt, a safety specialist with Mississippi State University's Extension Service, said kerosene heaters and other alternative heat sources are designed for use in well ventilated places, such as outdoor work areas. Houses with tight seals, caulking and vapor barriers are not good locations for extended use.

"There are two concerns with kerosene heaters: combustible materials that are too close to the heater and deadly carbon monoxide that people may not notice until it's too late," Willcutt said. "Winter power outages often prompt people to place alternative heat sources in areas they would not normally have them. Be sure there are no combustible materials near the heater. Also, monitor children and pets, and teach them to be very cautious around the heater. Be sure the heater has an emergency shutoff in case the heater is tipped over."

Willcutt said kerosene heaters should be a last resort because of the odors and fumes they give off. People with breathing difficulties such as asthma, allergies and bronchitis should not be exposed more than a few minutes. Never sleep with one in use. Any house that contains a kerosene heater needs a carbon monoxide detector.

Willcutt emphasized the importance of turning the heater off and allowing it to cool before refueling it outside.

"It's fairly easy to overfill tanks by accident, so it is important to have the heater outside and to wipe off residue afterwards," Willcutt said. "Keep kerosene and other flammable liquids stored in approved metal containers, in well ventilated storage areas, outside of the house."

Mississippi's State Chief Deputy Fire Marshal Millard D. Mackey said heaters need to be in good working condition and not damaged or altered before using. Any decrease in heater efficiency will increase the risk of carbon monoxide poisoning.

"Read and follow the instructions for use to the letter," Mackey said. "Use the proper fuel in the heater. Make sure to use white kerosene, which burns cleaner and gives off less carbon monoxide. Do not use in an area with flammable liquids, even outside, because the vapors can ignite."

Mackey said any house that might have a kerosene heater when power is off needs a carbon monoxide detector. Homes with gas appliances also need carbon monoxide detectors connected to the electricity with a battery backup.

Willcutt said fireplaces and wood stoves generally provide very little heat when screens and glass doors are in their safest position: closed.

"Opening glass doors and screens provides more heat but also increases the danger of sparks popping on people or anything close to the fire," Willcutt said. "It may help to choose wood that does not typically pop as much, such as red and water oaks when they are dry. Some of the other oaks, hickories and other types of wood tend to pop more."

If synthetic logs are used, follow the directions on the package. Never break a synthetic log apart to quicken the fire or use more than one log at a time. They often burn unevenly, releasing higher levels of carbon monoxide. Do not use flammable liquids to start or accelerate any fire.

"Don't use excessive amounts of paper to build roaring fires in fireplaces since that can ignite creosote in the chimney by overbuilding the fire," Willcutt said.