In summertime, we are tempted to wear as little clothing as possible to beat the heat. Unfortunately, that philosophy means that you are exposing a great deal of yummy looking skin to mosquitoes. The best chemical-free way to protect yourself from mosquito bites is to dress in long sleeve shirts, pants, and socks. Shirts should have tight-fitting sleeves and snug collars (keeps ticks out too). Shirts should be tucked in at the waist. Pants legs should be tucked into socks. The fabric should be lightweight and loose fitting. Thin, close-fitting fabrics will provide much less protection from bites. Wear light colors as mosquitoes are drawn to heat sources and dark colors are hot colors. Dressing this way when you know you will be in an area with high risk of mosquitoes minimizes exposure to the bloodsuckers and the chemicals. To further reduce chances of being bitten, treat clothing with an insect repellent. By doing so, you still limit the amount of exposure to both bug bites and direct skin contact with chemicals.
Avoid perfumes and scented skin lotions, shampoos, etc. These scents can inadvertently make you an attractive target.