ALERT: Do not plug space heaters into power strips!

HOUSTON, Texas (KTRK) -- With the temperatures dipping, Houston Firefighters are urging people to take extra safety precautions when using space heaters.

HFD says that a space heater was the cause of a fire that killed a woman in northwest Houston and injured her son.

The devices may keep your family warm as temperatures cool down, but they can be dangerous if not used properly.

"Most important keep it at a three-foot radius and do not put them on top of carpet," Houston Firefighter, Kenyatta Parker said "The radiant heat, people don't pay attention to it, the flame is hot but around that area, you have radiant that goes on the carpet and can catch fire."

Rachel Moreno, with the Harris County Fire Marshal, said there are several things you should look for when buying a space heater.

"What you want to look for is one, that the space heater has a safety feature that if it tips over it will automatically shut off," Moreno said. "The second thing is you want to make sure it's tested by a reputable company such as UL or Intertec because they make sure it meets all safety requirements."

With the help of firefighters at Cypress Creek Station 24, Eyewitness News found out just how quickly a space heater can catch fire, even one with safety features.

We put towels and cotton on top of a space heater and within six minutes we saw smoke and flames.

"It's really important to keep anything that burns, three feet away from a space heater," said Moreno.

Also, keep your space heater on a flat surface such as a wood or tile floor and avoid carpet.

Furthermore, don't plug your space heater into a power strip, instead plug it directly into the wall.