A lieutenant with the Butler Bureau of Fire said Friday that people who use external heaters in their homes in the winter, or those who use backup electrical generators, must exercise caution to avoid starting a fire, or building up carbon monoxide indoors.

Floyd Lohr said the Butler Bureau of Fire didn’t respond to any calls related to carbon monoxide alarms Friday, but one of the department’s lieutenants said the cold weather can escalate the risk of emergency.

“If they are using any exterior generators, keep them outside, run the electrical cords inside, do not cover them up,” Lohr said. “Extension cords can cause fire; do not overpower outlets. Only plug in necessary items, refrigerators, electric heaters.”