Well... I have a run of the custom ZIA neoprene/spandex fabric - all still rolled up.

I also have some spandex which I plan to "layer" somehow to something more breathable than neoprene, just because it so dang hot here! (Either that or move to Alaska!)
To be honest - I don't think I'd wear the costume outside here in the summer. 100+F is just too hot with the sun beating down on you... I can't stand it in normal clothes.

I think I would only troop inside or outside once it cools off to something tolerable.
In addition I can say is "Hydrate" is the key... I've seen people not do that and get pretty sick! (I thought I'd have to call 911 more than once while trooping!... but some people are stubborn!).