Dallas, TX – By HOLLY YAN, The Dallas Morning News

Vanessa Perez learned how deadly winter can be the day before it officially began.

Feeling the nippy weather, she turned on the gas heater in her new house just before going to bed Sunday night. She and her six children almost didn’t wake up the next morning.

“We should be dead right now,” Ms. Perez said.

Within hours, Ms. Perez’s house in the 2500 block of Winthrop Drive had filled with a deadly level of carbon monoxide.

Ms. Perez’s son Henry noticed the problem first. About 6 a.m., he tried to wake his mother because he had a headache and stomachache, but his mother could barely move.

“I was crying and screaming,” Ms. Perez said.

She called a friend for help, who came over and called 911.

When firefighters and paramedics arrived, they tested for carbon monoxide.

Dallas fire Lt. Joel Lavender said homes with more than 10 parts per million of carbon monoxide should be vacated. The Perez house had more than 600 parts per million.

Investigators determined the cause to be a gas furnace whose valve pipe was not properly attached. Instead of pushing carbon monoxide outside the house, the gas stayed inside, silently poisoning Ms. Perez, her children, and a family friend and her 2-month-old child.

“Carbon monoxide is odorless and colorless,” Lt. Lavender said. “Most people don’t get a chance to make a second mistake with carbon monoxide.”

The nine people in the house were taken to Presbyterian Hospital, where they were treated and released within seven hours.

Ms. Perez did not have a carbon monoxide detector, but she quickly added it to her Christmas list.

“It’s expensive, but it’s your life,” Ms. Perez said. “I wish I had known about this ahead of time. None of this would have happened.”

In addition to having working detectors, Lt. Lavender said everyone with gas appliances should have them professionally inspected every year.

Ms. Perez lamented that the family would go without heat and perhaps Christmas presents as the furnace gets repaired, but she was more grateful that her family is alive.

She said if not for the actions of her 6-year-old son, “I think my family would be planning our funeral right now. It’s a miracle that we’re here.”