Of course, the best way to avoid being bitten by a bug is to cover up your body as much as possible. But in the sweltering heat, this might not be the most appealing option. A good alternative is to wear insect-repellent clothing, particularly clothing containing permethrin, a synthetic chemical insecticide.
Permethrin-treated clothing can remain effective for several months. But washing it can reduce its effectiveness. If you wear and launder permethrin-treated clothing every day, it will remain effective for about two weeks. You should reapply permethrin after about five washings.
On the down side, the jury is still out on the safety of permethrin. While it's not toxic when applied to clothing, it should not be applied directly to the skin. Although the Environmental Protection Agency asserts that the benefits of permethrin outweigh the risks, it lists the insecticide as a likely carcinogen if handled improperly [source: EPA].