Do your holiday plans include travel abroad? The Mayo Clinic, Jacksonville, FLa., offers advice to help avoid illness.

"Travelers should prepare for any trip by assessing their risk for illness and planning accordingly," says Dr. Lisa Brumble, an infectious disease specialist at Mayo Clinic. Will you be staying in an urban or a rural environment, a five-star hotel or a private home? Will you prepare your own meals or eat out?

Brumble says travelers should also determine if their medical condition prompts additional travel considerations. For example, air travelers with certain conditions that may require oxygen need to check with their physician first about the potential need for oxygen. Then check with their airline about availability.

Air travelers are often advised to do periodic calf-flexing exercises or move about on long flights to prevent a deep vein thrombosis (DVT) brought on by blood clots forming in the legs. "Your risk of developing a DVT is very small," Brumble says, "unless you have any pre-existing risk factors, such as previous history of DVTs, current estrogen replacement therapy, are pregnant or have had a recent surgery or trauma involving the legs or abdomen." Those at high risk should discuss travel plans with their physician, who may suggest a low molecular weight heparin injection before flying.

To combat jet lag, Brumble advises travelers to spend one day of rest for every six time zones crossed. Avoid heavy meals, caffeine and heavy alcohol use. "Some travelers take melatonin to resynchronize the body's internal clock," Brumble says, "but its benefit is unproven.

A simple tip is to alter your sleeping pattern a week before departure and to engage in an outdoor activity in the sun upon your arrival."

Too much sun, whether it's on Northern ski slopes or Southern hemisphere beaches, is still bad,so remember to pack sunscreen with an SPF greater than 15.

Sensitivity to the sun's UVA rays increases if you're taking tetracyclines, sulfa drugs or oral contraceptives. You can lessen your risk of food poisoning, particularly in areas of suspect food preparation practices.

All raw food is subject to contamination. Avoid salads, unpasteurized dairy products and uncooked fruits or vegetables unless you have thoroughly washed them yourself. Eat only thoroughly cooked foods while they are still hot. "If you can't boil it, heat it or peel it, don't eat it," Brumble says.

In areas where the water supply is questionable, ice made from the tap water or using tap water to brush your teeth can subject you to a waterborne illness. To avoid this, Brumble says the most reliable way to decontaminate water is to boil it for one minute. Portable water filters vary in activity, and chemical decontamination with chlorine and iodine are not foolproof.

What is safe to drink: beverages like tea or coffee made with boiled water; canned or bottled, carbonated beverages; beer and wine. It's better to drink directly from the can or bottle than from a questionable container. What do you do if you develop traveler's diarrhea?

Keep hydrated by drinking oral hydration solutions such as packaged Gatorade made with boiled water. Bismuth subsalicylate (Pepto-Bismol) is about 65 percent effective in suppressing harmful intestinal bacterial growth. But don't use it for more than three weeks. Antimotility agents such as Imodium are helpful for mild diarrhea.

"The Centers for Disease Control does not recommend prophylactic treatment with antibiotics to prevent traveler's diarrhea," Brumble says, "so prevention is the best medicine."

If you do need medical attention overseas, Brumble suggests contacting the International Association for Medical Assistance to Travellers (www.IAMAT.org) for a listing of international physicians who care for travelers.

Source: Mayo Clinic, www.mayoclinic.org