Definitely have your dog on flea/tick protection as well as Heartworm preventative (hopefully already on this!). I use NextGard for fleas/ticks, and Heartgard Plus for Heartworms; both are chewables. They work well for us down here in the deep south.
We bought folding beds at Camping World for our little dogs, which we put in their x-pen. It keeps them off the ground and out of the sand. We also use the top half of an old beach umbrella to shade them from the hot sun. Here's a photo to better show what I'm talking about:
