Weathergirly - then you should be happy with the new announcement. The more 800's the less chance of you sweating down the back. The 300's AC packs aren't as efficient as the 800 - there are no cooling issues on the 800, even in 32 degrees on the ground.
I assume you were on a 300, and if it's any consolation, it gets just as hot in the front, there literally is nothing the crew can do - yes, window blinds would help in this situation, but alas, we don't have them.