As far as the what to wear in August conversation..
As lightweight as humanly possible. I would wear skirts or dresses (with the bike shorts as someone suggested) or capris or the dreaded shorts.
I stick to Capri's myself. I can honestly tell you the only time I ever commented on what someone was wearing was in Epcot last August when someone walked by in jeans. I literally remember saying to my husband "Now that is heat stroke waiting to happen"

I too am very pale, short and plump and I could care less. It is just too darn hot for pants.
Take your hottest day at home, add in vicious humidity and then imagine being out in it all day long.
ETA) My dd went through a very self conscious phase where she hated shorts. She was 14 and you know how much pressure young girls put on themselves.. she's beautiful..anyway..On that trip she came out of the bathroom in shorts that I hadn't seen her wear all summer. I asked her what happened to the "no shorts" policy. She said "It's a million degrees, I'm over it" lol.