I wouldn't say its the norm but I have endured the occasional sauna flight on BA. Personally, this is one thing that can destroy the flight experience - i'd much rather sleep bolt upright, strapped to a gurney in a cool WT galley at the rear of the aircraft than lie flat in Dante's inferno.

I'm usually a passive traveller, happy to accept my lot but when it comes to excessive cabin temperatures, I will not hesitate in asking the crew to turn it down. As far as I am concerned, the cabin lizards can put another layer on - this is far fairer on humanity than expecting me to remove all of mine.