The safest bug repellent is proper clothing. Wear a full-brimmed hat to protect your head and the back of your neck. Make sure your ankles and wrists are covered. Tuck pant cuffs into socks, and wear light-colored clothing. This clothing is less attractive than dark clothing to biting insects and makes it easier to spot any ticks or insects that have landed.

Wear lightweight gloves, particularly in the garden. Check clothes regularly for bugs. Use protective netting around sleeping and eating areas to keep the bugs at bay.

Even with proper clothing, when visiting an area with many insects, bug repellent should be used. To avoid skin irritation, apply insect repellent to clothing. Test the repellent on a small area of clothing first to determine if it will bleach or otherwise discolor the fabric. If areas of your skin are exposed, you will need to apply the repellant there as well.

Whenever you are in mosquito, sand fly, or tick territory, chemical insect repellents are necessary. The best repellents contain the chemicals DEET, indalone, Rutgers 612 (2-ethyl-1,3-hexanediol), or dimethyl phthalate (DMP). DEET has become the most common and most popular. R-326 (di-N-propyl isocinchomeronate) is useful against biting flies. Use chemical repellents sparingly. Avoid using directly on sunburned skin.

Despite their popularity, bath oils or skin sticks provide only one hour of protection against bugs compared with products containing 25% DEET, which last up to 7 hours.

Another type of repellent called Picaridin has been available in the United States since 2005. Picaridin has less odor than DEET and doesn’t damage plastics like DEET. It lasts about 4 hours and works as well as DEET if it is reapplied.

If using both sunscreen and bug repellent, apply the sunscreen first and wait 30 minutes before applying the bug repellent.

To avoid toxicity from insect repellents:

• Apply repellent sparingly and only to exposed skin or clothing. Keep out of eyes.
• Avoid using high-concentration products on the skin, particularly on children.
• Use a lower concentration of DEET on pregnant women and small children.
• Never inhale or ingest repellents.
• Wear long-sleeved clothing and apply repellent to fabric rather than to skin.
• Repellent should NOT be used on children's hands because they are likely to rub their eyes with them or put them in their mouth.
• Children 2 and younger should not have insect repellent applied to their skin more than once in a 24-hour period.
• Wash repellent off your skin after the risk of being bitten by an insect is gone.

Fradin MS. Protection from blood-feeding arthropods. In: Auerbach PS, ed. Wilderness Medicine. 5th ed. Philadelphia, Pa: Mosby Elsevier; 2007:chap 41.