I have been regularly going to Egypt during July or August for the past ten years. We are a family of four from the UK, for us it has offered the best diving for the kids during summer holidays without travelling too far. Heading back again this year in August.
We really haven't found it too bad. In all the tourist hotels AC is very good, so whenever you are inside it is cool. To give you an idea on how we find the temperature; if we have breakfast before 8am we normally sit outside in the shade, later than that we would probably eat indoors with aircon, then lunch inside and dinner outside. If I go for a run I am out at 6am as it gets too hot otherwise. There are a few hours (maybe 12-3) in the middle of the day when you really notice the heat if you are walking about in the open, but if you sit in the shade by the pool it is fine. There is often a gentle breeze so that helps to keeps things cool.
If you are regularly in the water either diving, snorkelling or in the pool then I wouldn't worry about the heat, get up early and take a nap in the room after lunch if you want to miss the hot part of the day. It stays warm into the evening so you can sit around the pool until sunset.
On a liveaboard (or a day boat) I have never noticed the heat at all, and it is great to get out of the water after a night dive and feel warm.
Personally I wouldn't do an inland tour at this time of year as I think it could be way to hot to enjoy the sites, although whenever you were inside it would probably be fine.
I was about to add a comment about being safer in Hurghada than the US, but see that someone has beaten me too it.