Even when you're doused in bug repellent, wearing your head net and scarfing down lunch on a windy summit, you still need to make sure your clothing provides the utmost protection. Wear long sleeves and long pants, even in warm conditions, to give your skin a protective barrier from the biting.
Dressing in light colors also keeps mosquitos away, since they have an easier time seeing dark colors than light. Rinsing any sweat from your head, neck and face is another preventative measure you can take, as mosquitos are attracted to sweat.
While no single method of repelling mosquitos is foolproof, having a multi-pronged approach to mosquito management will help keep your bites to a minimum so that you can maximize your time in the great outdoors.