Stars like Diane Kruger and Rachel Bilson are looking hot in the heat thanks to straw chapeaus. "A great summer hat gives you style with protection from the sun," says designer Tracy Watts, whose hats are worn by Halle Berry and Jennifer Lopez. When shopping straw, Watts recommends looking for a hat of sewn braid which has "more durability and softness" than a woven topper. And don't forget the fit. Says Watts, "A hat fits properly when it sits just on top of the ear and is not too tight or too loose."

BUY ONLINE NOW Browse the hottest summer hats!