This question already has an answer here:
On my recent flight to Tokyo on UA I found the cabin immensely cold and not only did I ask for an extra blanket, I also asked if the temperature could be raised. The flight attendant did not refuse and actually said she would check - and probably did something - because I did feel better after a while (unless I just got used to the cooler temperature). However on my return flight it was just the opposite and the flight was extremely warm. So I'm wondering, is there not an FAA standard for in-flight temperature (and probably pressure) or it is fairly arbitrary - within a range, of course?