When shooting in the hot sun, you will often run across situations where you have a lot of shadows on your subject. To get around this, try using a fill flash. Simply connect your speedlight to your camera and start shooting. For a more balanced, diffused light, use a modifier on your speedlight like that MagMod MagBounce.
Read more about the best ways to use a fill flash in “Utilizing a fill flash during bright, sunny conditions”