Hartford, CT – It was a close call for a mother and her unborn son in Vernon after she said she nearly died from carbon monoxide poisoning.

Cheyenne Brennan and her boyfriend, Steve Gankofskie, now want to warn people about the dangers of the silent, odorless and colorless gas.

Both said they were spending a normal Sunday night at Brennan’s home on Dobson Street. However, Brennan remained bedridden and strapped to monitors Tuesday night at Hartford Hospital.

“They gave both of us oxygen,” she said.

The couple said they should have known something was wrong with their carbon monoxide detector started going off Saturday night.

“That thing went off before we even had symptoms,” Gankofskie said.

They said they opened windows and changed the detector’s batteries just to be sure. However, they closed the window before going to bed.

They woke up to the carbon monoxide detector blaring yet again.

Now, they said it was too late. They were sick to their stomachs.

“We both had severe headaches, and when I went to turn off the alarm, I felt dizzy, nauseous,” Brennan said.

Doctors said she was poisoned. The effects from carbon monoxide can be felt at 50 parts per million. Gankofskie said when firefighters arrived and tested the levels, they clocked in at 286 parts per million.

Firefighters said the culprit was a clogged chimney flue.

With the possibility of brain damage, the couple was rushed to Hartford Hospital.

Gankofskie was fine, but Brennan, at six months pregnant, was put into a hyperbaric chamber to get pure oxygen into her system for her and the baby.

“I felt kind of tired when I went in there,” she said. “I never been in one before.”

Brennan and her child have been receiving care around the clock.

“The baby looks good, the baby is moving well,” said Dr. Kelly Johnson-Arbor of Hartford Hospital. “The baby hasn’t had any signs of distress so far.”

Brennan and Gankofskie said they have advice for other people.

“Go spend $20 on the alarm and use it,” said Gankofskie. “Put it up. Change the batteries. If it goes off, get out of your house.”

Doctors said it’s a good idea to change the batteries in your smoke and carbon monoxide detectors for Daylight Saving Time.

Brennan said she has one more treatment in the hyperbaric chamber, but she should be OK.