I agree, Blanche. I've always feared freezing or it becoming too hot. So sad.
To be honest with you, Jemma, so much can go wrong. I've had dogs die because a flight was delayed and they were left sitting out on the tarmac in their crate in the sun (Not my own dogs, but the dogs of friends and family), put in a corner in the baggage handling room and crate got covered up by other luggage so dog overheated, and the technical breakdowns of the actual cargo hold, like this pug suffered.