GAINESVILLE — Already feeling nostalgic about that August heat wave?

Temperatures in much of Northeast Georgia dropped below the freezing mark by early this morning, and afternoon highs won’t climb above the mid-50s. Tonight is forecast to be even colder, with temperatures falling to the upper 20s.

The low in Gainesville this morning was 30 degrees, according to the National Weather Service Web site.

Sean Ryan, a meteorologist with the National Weather Service in Peachtree City, said the wintry blast is right on schedule.

"For Gainesville, the average date of first freeze is between Nov. 1 and Nov. 10," he said.

The cold nights will not be enough to kill most vegetation. But homes may get chilly enough that people will want to turn their heat on, and that has local fire officials worried.

"The change in weather always increases our chances of residential fires," said Gainesville Fire Marshal Jerome Yarbrough. "The biggest problem is space heaters. This time of year, a lot of people will plug in a space heater because they don’t want to turn on their main heat."

For some residents, there is no "main" source of heat. "A lot of the older mobile homes have no central heating," said Hall County Fire Marshal Scott Cagle. "People are using alternative sources such as kerosene heaters and space heaters."

That’s a concern, he said, because an old mobile home is "already like a tinderbox," made of materials that can catch fire easily.

If people must use space heaters, Cagle urges them to allow three feet of clearance around the appliance. "Keep it away from anything combustible such as couches or curtains," he said.

Cagle said there is still a lack of education about how dangerous space heaters can be. "I’ve seen people hang laundry on them to dry," he said.

Fireplaces are another potential hazard. "We have a lot of chimney fires this time of year because of neglect or poor maintenance," Cagle said. "Creosote and debris can build up inside the chimney, and there may be bird or squirrel nests. Also, cracks in the pipe can cause attic fires."

He recommends calling a chimney sweep to perform an inspection before using the fireplace, although by this time companies are usually booked solid with appointments.

Even people lucky enough to have central heating should take precautions. "People should already have gotten their heating system checked by this time, especially if they live in an older home," Yarbrough said. "At the very least, you should change your furnace filter."

He warns that the first time residents turn on their furnace for the season, they should expect a strong odor from burning dust.

"If there’s a big build-up of dust, it can actually start a fire within the ducts, so don’t turn your furnace on and then leave the house," Yarbrough said.

Cagle said people should make sure that the flame on their pilot light is blue. "If it’s flickering orange, that’s a problem," he said.

An orange flame can indicate incomplete combustion, which can give off carbon monoxide.

"If you have a kerosene or propane heater, or a wood-burning stove, your home needs a carbon monoxide alarm," Cagle said. "If that alarm goes off, treat it the same as you would a smoke alarm. Get out of the house and call 911."

He said every family should have an escape plan in place in case of a fire. And as always, they should have smoke detectors that actually work.

"If you didn’t change your smoke alarm batteries when you turned the clocks back (Saturday night), do it now," Cagle said.