Thanks for all the replies. I fly the Airbus so yes there are certainly some cold areas on the flight deck. Especially behind the sliding window although my lunch box is too big. Yesterday just gave it to the senior who put it in a cool bag. I have to admit I'm not sure what the necessity of keeping food chilled is but would prefer to be on the safer side.
Probably will get into bringing frozen food at some point. Was just wondering if there was any cool packs or similar that I can get through security but as long as I can pass on my food to be put into the cool bag shouldn't be a problem.