Thanks for the info so far. Just to clarify, I work for a catering company and we had an issue with a catering pod that malfunctioned (they have their own inbuilt cooling system) causing the return sector catering to spoil. So hence my question that is it possible for the hold temperature to be maintained between 0 - 8c which is the acceptable range for the perishable food. If this is possible then it could save ourselves and the airline possible future delays and money whilst down route catering is sourced with all its associated costs. The information I require is specific to the VA 747-400's.