How to dress stylishly and stay cool in phoenix?

Ok it's getting dangerously close to summer here in Phoenix ( it was like 90 degrees today and it's still march) and i was wondering what some stylish summer clothes are for guys? i'm a 19 yo college guy and i don't want to dress like a frat boy douche. But i would definitley like to dress more fashionably and "grown up." as oppossed to my usual summer wardrobe of a t shirt and ie shorts any suggestions?