I love that time, we've been three times during the last two weeks of August (4 times if you count our honeymoon back in '99!) and have really enjoyed it. I'm tentatively planning for August 2016, although if our exchange rate stays as terrible as it is now, that might not happen...but a girl can dream, right?
I am not worried about the heat as much. We are here right now and the first few days it was 100+ and has been really hot everyday. So I think we will be OK. We usually go to WDW in July so are pretty used to the heat.