But facing the fact that it was very cold up there, why didn`t they all have wired jackets Andrew? Perhaps far from all planes were prepared for heating? I find it hard to find information about this on the net. Till now I have just been informed that it was 24 volts DC that was used for the heating system.
Interestingly, the guys on the extreme left and right seem to be wearing only battle-dress jackets. Maybe those guys are the pilot and co-pilot, and sat in the cockpit with some heating?