Summer clothes?

Hello everyone, I am posting on this community to solicit advice on avoiding heat stroke while not looking like a fool. Currently I own several 95% polyester 5% spandex short-sleeve button-ups as well as one 100% linen long-sleeve button-up. I find both to be quite suitable for hot weather, but would love suggestions that aren't T-shirts and button-ups. Additionally, what options are there for summer pants? And what actually looks good with shorts? When I wear them I look like a camp councilor - or worse, a kid attending summer camp. Feel free to discuss dresses and skirts as well, although I am personally not interested. Oh yes, and I suppose summer hats could be useful too. Thank you in advance.