Mom angered with United Airlines after she says baby overheated during tarmac delay

A mother on a United Airlines flight last week said she feared for her infant's life when she says he became overheated during a tarmac delay in a Denver heat wave.

Emily France, 39, told The Denver Post that she and her 4-month-old baby boarded the flight to El Paso around 1:20 p.m. last Thursday at Denver International Airport, where temperatures had climbed to 90 degrees that morning.

Poor weather along the route delayed the flight, resulting in passengers waiting on the plane at the gate, but according to France, crew members did allow passengers, herself and her child included, to step off the aircraft and onto the jet bridge to cool off.

Even when the air conditioning is functioning properly, as United indicates it was that day, it's not unusual for the cabin to get warm when a plane is sitting on the tarmac.

After getting back on the plane, the passengers on United Express flight 4644 continued to wait, but this time the plane had pushed back from the gate and was sitting in a holding area on the tarmac. France told The Denver Post that flight attendants brought her garbage bags of ice, but she says her son Owen began to struggle in the hot aircraft,

"His whole body flashed red and his eyes rolled back in his head and he was screaming," France told the paper. "And then he went limp in my arms. It was the worst moment of my life."

That was when crew members called for paramedics and the plane returned to the terminal.

According to United Airlines, the aircraft was back at the gate about 11 minutes after the captain's call for paramedics. But according to France, it took approximately 30 minutes to return to the gate.

United Airlines told ABC News that paramedics tended to the child, and a Denver International Airport spokesperson told ABC News that medics were called Thursday afternoon for an infant suffering from shortness of breath.

According to The Denver Post, France's son was home on Friday after receiving treatment at a Denver hospital.

In an emailed statement to ABC News, France said: "It is not right for United to expose infant passengers to temperatures that are dangerous for them. And it is not right that they can't evacuate them quickly. I am sharing Owen's story in the hopes that this never happens to anyone ever again."

United told ABC News it apologized to the customer and is actively looking into the incident.

"This should never have happened," United said in a statement. "We are profoundly sorry and apologize to our customer and her child for the experience they endured. We are actively looking into what happened to prevent this from occurring again."

A spokesperson for United also said that medical care was provided to the child within 16 minutes of the captain's call for paramedics.

The airline's policy says it will "maintain comfortable cabin temperatures, and ensure adequate medical attention if needed while the aircraft remains on the tarmac."

Federal regulations allow planes to remain on the tarmac for up to three hours without deplaning passengers, and stipulates that "while the aircraft remains on the tarmac ... medical attention must be available if needed."