Several people passed out on an airplane in Las Vegas on Monday when the plane was stranded on the tarmac for four hours without air conditioning amid a 111-degree heatwave.

The Delta Air Lines flight at Harry Reid International Airport was queued behind several other planes, ready to depart for Atlanta. However, the pilot then announced they must turn back due to multiple emergencies, according to a Fox News field producer who was on the flight.

As conditions deteriorated, passengers were instructed to remain seated and wait for paramedics to board the plane. At least five individuals were carried off the plane on stretchers. The pilot advised passengers to “hit your call button if you’re having a medical emergency.”

Passengers were given the option to disembark the plane, but were informed it could take several days to secure another flight.

The passengers were eventually removed from the plane, and the flight was rescheduled for Tuesday at 7 a.m. However, the flight was subsequently canceled, and customers received an apology and compensation.

Delta stated that they are investigating the cause of the incident.

“We apologize for the experience our customers had on flight 555 from Las Vegas to Atlanta on July 17, which ultimately resulted in a flight cancellation,” the airline said. “Delta teams are looking into the circumstances that led to uncomfortable temperatures inside the cabin and we appreciate the efforts of our people and first responders at Harry Reid International.”