Does anyone have any tips for summer fashion? How about tips for dealing with a hot and sweaty binder?

That is a tough one. Depending on your size, you can sometimes get away with wearing a stiff, loose shirt with nothing under it. I did that the summer before i transitioned, but i was very small.

Check the company where ever you buy your binders from and see if there are any light weight binders that only have to go around your chest once. You might want to put some baby powder under the binder as material that is tight on sweating skin can cause some pretty nasty rashes and friction burns.

sam1234

What about some button down shirts ?

And silk is said to be quite cool on the skin (I'd just watch the quality... there are some artificial ones which are not nice to wear). There are other fabrics, like linen, which are also very pleasant to wear when its warm...

hugs

For the heat:
How about carrying around a pack of wet tissues? They're like wet napkins, though some are soaked in, alcohol, I think, to make a cooling sensation on your skin. Or an instant cold pack. Just carrying around one in your pockets and holding it, or something.
Also, drink a lot of water!

Additionally you could try buying a half-binder, I imagine these are cooler than the full-lengths.