In the tropics, insects can transmit serious illnesses such as malaria, yellow fever, and dengue disease—some potentially life-threatening. These diseases are best prevented by personal protective measures, in other words, mosquito repellent. In some cases (e.g., malaria or yellow fever), a preventive drug or vaccine is available as well but should never replace personal protection measures. Travelers to areas where insects that transmit these diseases may be present can help minimize their risk by following the insect precautions and protective measures below.

• Wear clothing that exposes as little skin as is practicable.
  
  
• Apply a repellent containing the insecticide DEET (concentration 30 to 35%) or picaridin (concentration 20% or greater for tropical travelers).
  
  
• Picaridin has a pleasant smell, an advantage over DEET.
  
  
• The repellent should be applied to all exposed nonsensitive areas of the body. Frequent application ensures continuous protection.
  
  
• Treat outer clothing, bed sheets, pillows, etc. with permethrin when traveling in an area of high risk for malaria or other mosquito-borne or tick-borne diseases.
  
  
• If you are not sleeping in a sealed, air-conditioned room, sleep under a permethrin-impregnated bed net when at risk of malaria. Regularly check the net for rips and tears, and keep it tucked in around the bed at all times. Ensure that all open windows have insect screens.
  
  
• Use an aerosol insecticide before going to bed.
  
  
• In areas where tick-borne disease is a risk, perform a full body check at least once a day.