You can only really look stylish in the heat if you're naturally very slim, I reckon. There are several mums at my DD's school who have that tiny-framed, small-breasted, gamine look going on, and they look wonderful, drifting about in loose-fitting, floaty clothes that makes anyonre bigger than a size 10 and a B cup look like a ship in a ship in full sail.
It's definitely a shape thing, not just a weight thing. Even at my thinnest, when I was a size 10, I could never have pulled off that look, I was still too curvy.
So jealous. I want to drift too!