A dream vacation turned into a nightmare for Sunwing passengers who say they were stuck for hours on a hot plane while their flight was delayed in Cancun.

Passengers who arrived at Toronto’s Pearson International Airport said they were stranded on the plane without air conditioning on the tarmac in Cancun for hours before they were eventually let off. Later, they boarded the plane for a second time before their flight was eventually cancelled.

The whole ordeal lasted nearly 24 hours.

Ulises Concepcion Velazquez, a passenger, told CP24 that “the heat was truly bad and we asked several times for them to let us out.”

She and other passengers slammed the airline for its lack of communication.

“I think the biggest part for me was that there were so many people who were panicking and nobody had anything to say,” Angel Kivinen told CTV News Toronto. “Flight attendants just kind of looked at you…tell us what’s going on.”

Velazquez shot video while onboard the plane, where at least one person can be heard yelling, “Shame on you! There is a child crying. Shame!”

Passenger Azam Hassam said it was “one thing after another,” with airline employees giving several reasons for the delay, including the cargo doors not closing and the engine not starting.

In an emailed statement to CTV News Toronto, Jacqueline Grossman, a spokesperson for Sunwing, blamed the delay on mechanical and maintenance issues.

“Since the grounding of the Boeing 737 MAX, regrettably some of our regular operations have been disrupted, as we have had to sub contract the services of other carriers,” the statement said.

Grossman said that the “plane was not serviceable” and that “a replacement aircraft was sourced to operate” on Saturday morning.

Sunwing said the same mechanical issue also affected the plane’s air conditioning system.

“We remain extremely apologetic for the delay to today’s service and will be offering our customers compensation,” the statement concluded.

Passengers were put up in up in an all-inclusive resort for the night and the rescheduled flight took off Saturday morning.