A hospital in Quebec City declared a Code Orange on Thursday after airline passengers were sickened by carbon monoxide.
The plane was on the tarmac at Jean Lesage International Airport and undergoing de-icing at 10:45 a.m. when people suddenly started feeling unwell.
Passengers were taken off the plane and multiple ambulances were sent to the airport.
At least 12 people were feeling extremely unwell with some experiencing dizziness, vomiting and itchy eyes.
"For the moment, we are talking about a problem with the ventilation system during the de-icing of the aircraft," airport spokesperson Laurianne Lapierre told The Canadian Press. "The airline is leading its own investigation to determine the source of the problem."
Saint Sacrament hospital declared a Code Orange -- meaning the hospital was preparing itself for a mass influx of patients exposed to hazardous materials.
According to the airline five passengers were taken to hospital.
The flight affected was Air Transat flight 782 heading to Fort Lauderdale with 180 passengers. According to Air Transat's website, it was a Boeing 737.
Debbie Cabana, a spokesperson for the airline, said a new flight is scheduled for 5 p.m.
Lapierre told The Canadian Press she did not know if the hospitalized passengers would be able to make the flight. "We obviously hope they can leave for Florida rapidly," she said.