Before You Buy Bug Spray

Insect-borne illnesses are serious summertime problems. Protect yourself with a repellent containing DEET, the most effective active ingredient. The EPA and CDC say DEET is safe; risks include skin irritations. DEET doesn't kill bugs; instead, it forms a barrier between skin and insect, making users unattractive to pests.

1. Go low Don't use products with more than 30% DEET, says Dr. William Weil of the American Academy of Pediatrics. Stronger ones aren't more effective. In fact, 10% is plenty if you'll be out less than two hours; 30% should last all day.

2. Skip combos Avoid products with both DEET and sunscreen. Sunscreen should be reapplied often throughout the day; DEET should not.

3. Use safely Don't apply DEET to irritated skin, around the eyes or mouth, or to the hands of children (lotions may be safer than sprays). Use it only on exposed skin, not under clothes.