Air Canada spokesman Peter Fitzpatrick told ABC News today that while such a heater would not normally cause a problem, it was a concern on this flight because there was a live animal in the hold.
"Air Canada's pilots are professionals who are responsible for the entire flight. As soon as the crew became aware of the temperature issue, the Captain grew rightfully concerned for the dog's comfort and well-being," Fitzpatrick said in a statement to ABC News.
Citing privacy concerns, Fitzpatrick would not release the name of the animal's owner or the name of the pilot but Canadian news site City News reports that it was a 7-year-old French bulldog named Simba.
The pilot made the decision to divert to Frankfurt because it is a hub for the airline and Fitzpatrick said that since there were so many of Air Canada's planes there, that the pilot knew he would be able to turn the flight around quickly.
Fitzpatrick said the plane was in Frankfurt for about an hour, and the dog was put on a different Air Canada flight.
"While we recognize this was an inconvenience for our customers, the overall reaction was positive, particularly once people understood the dog was in potential danger but safe as a result of the diversion," Fitzpatrick said.
All told, Fitzpatrick said the customers landed in Toronto 75 minutes after their originally scheduled arrival time.
John Nance, a former commercial and Air Force pilot who now works as an aviation consultant for ABC News, said that the move is "unprecedented."
"This is very laudatory because we have some airlines that don't care if they break guitars, kill dogs and cats," Nance said. "I would think that Air Canada is due some public praise here, especially if they support their captain.”
Nance said that the cost of the diversion, which Air Canada declined to answer when asked about by ABC News, would be a reason against making such a diversion.
"I would think that today's airline [industry] is so profit driven, and Air Canada is no exception, and it costs a huge amount of money for a diversion of an aircraft, that this is something that a captain does not do lightly," Nance said.