Victoria, TX- Ten people were overcome by carbon monoxide fumes Thursday night in Yorktown.

First responders were sent at 7:49 p.m. to 321 E. Main St., where an unconscious person was reported at Masonic Lodge No. 76, said DeWitt County Sheriff Carl Bowen.

He said eight people were treated and released at the scene.

Two people were transported to Cuero Regional Hospital in stable and good condition, Bowen said.

“It was a precautionary measure,” he said.

Bowen said he thinks the carbon monoxide, or CO, was coming from a furnace, but it is still under investigation.

He said investigators planned to wait for the carbon monoxide levels to come down to make a more accurate assessment.

“We are in the middle of a cold season,” Bowen said. “People need to be careful when they use any type of heater.”

If people have an older heater model, Bowen said it should be checked by a local gas company and have it cleaned regularly.

He said people who own newer heater models should still be cautious.

“If you don’t have a carbon monoxide detector in your house, put them in,” Bowen said. “Even new equipment can fail.”

Last week, authorities in Central Texas said three relatives on a hunting trip were believed to have died of carbon monoxide poisoning inside a box trailer that was converted into a cabin, according to The Associated Press.

Brown County Sheriff Vance Hill said propane heaters were used to keep the cabin warm, but the structure didn’t have proper ventilation. He said there was no way for the poisonous fumes from the heaters to escape.

The trailer was on a ranch between Brownwood and Bangs, about 100 miles west of Waco.