B.D.
Something I've learned in my nutrition classes is that the brain can't differentiate between thirst and hunger. So especially in this heat where your body uses SO much water it's so very easy to get dehydrated. When you are dehydrated your brain will be sending a need signal, and most people will think it's hunger, but it's thirst. With him still being dry, that is what made me think that it could thirst instead. Let him drink a glass of water, and wait a little bit, if they are still hungry then go ahead.
As for the potty training.... sometimes in the middle of the night they are just sooo tired, they really have no desire to do anything. If you feel he really should try to go potty, then put him on it, and maybe read to him.
Ahh the life of a mommy... uninterrupted sleep is something we wish for!