Shirts are soaked, salt is clumped, and the hot Latin beat on the street is wilting. It's summer in South Florida, prime time to chill at Sonny's Gelato Café(2151 N. Federal Hwy., Boca Raton, 561-362-0447). Gelato contains a lower ratio of butterfat and air than regular ice cream, which makes it denser and more intensely flavored. And speaking of intense flavors, try Sonny's hazelnut pistachio, maple walnut, or tiramisu, three of 18 varieties you can mix and match atop a cone or in a neat plastic container. Then again, mango or watermelon Italian ices might be even more refreshing. I'm not so sure about the cotton-candy flavor. Sonny's has plenty of outdoor seating, but I recommend taking your licks inside the remodeled, air-conditioned café to avoid meltdown.