Nothing can ruin a vacation faster than someone getting sick. Whether you’re planning a trip just an hour away or across the ocean, there are many things you can do to stay healthy while away from home.

See your doctor before you go

Get a checkup before you go on vacation. Ask the doctor if you need any vaccines or preventive medicines. Some countries require vaccines that you wouldn’t normally need in the U.S. Make plans to get everyone vaccinated at least six weeks before you leave.

If you take any medicines regularly, make sure you have enough to last throughout your trip. Running out of a prescription medicine can be inconvenient — or even dangerous —  if you’re not near your doctor or pharmacy. If possible, keep your medicine with you in a carry-on bag so you have it with you at all times.

Avoid traveler’s diarrhea

Traveler’s diarrhea is the most common travel-related illness. It can happen nearly anywhere if you eat contaminated food or drink contaminated water. Lower your risk of getting it with these guidelines:

•  Eat only cooked food served hot.

•  Avoid eating food from street vendors, if possible.

•  Don’t eat or drink unpasteurized milk or dairy products.

•  Avoid eating raw seafood or undercooked meats.

•  Avoid tap water and ice on airplanes and in places where water may not be safe. Drink only commercially-bottled water and beverages.

•  Use bottled water to brush your teeth when traveling abroad. Don’t get shower water in your mouth.

•  Wash your hands thoroughly and often. Be especially careful about washing hands after using the bathroom and before eating.

•  Consider bringing some anti-diarrhea medicine with you in case you get sick. Make sure you stay hydrated with water, electrolyte drinks, and/or sports drinks.

Tell bugs to buzz off

Mosquitoes can spread disease, both in the U.S. and abroad. Protect yourself by wearing repellents with DEET. Use bed nets for international travel in areas where bugs are a problem. If you’re traveling to a country with a higher risk of malaria, ask your doctor about preventive medicine to take before you go on your trip. Be sure to also pack lightweight clothing that covers the arms and legs to keep bugs off.

A few simple precautions can ensure you have a safe and healthy summer vacation.