First, visit your doctor. "If you have a medical condition, it's important to check with your doctor about precautions for traveling," says Warren Rovetch, author of The Creaky Traveler books, targeted to travelers who are "mobile but not agile."

Make sure you do some research on the health-care systems in the countries you'll be visiting. Many exotic places, such as Costa Rica, China and Thailand, offer good services, says travel expert Arthur Frommer, of Frommer's travel guides. But some destinations, such as Vietnam, that are growing in popularity do not.

Also, check out the health conditions. The Centers for Disease Control and Prevention provides information on diseases worldwide and the precautions you should take (www.cdc.gov/travel; 877-394-8747). The World Health Organization (www.who.int/ith) lists countries that require vaccinations and provides other health-related information for overseas voyagers.

Once you're satisfied that your destination will not present any undue health problem, take these steps to help ensure a healthy trip.

Review your health insurance. Medicare does not cover you while you travel abroad, although some Medigap policies do. Many insurance policies don't pay for medical expenses overseas, so check your coverage carefully.

If you need coverage, Frommer says, "it's an absolute necessity to get a good comprehensive policy." He suggests checking InsureMyTrip.com, which offers policies from major travel-insurance companies.

Make sure the policy covers medical evacuations, which could cost you $50,000 without coverage. Also check for exclusions, such as injuries resulting from scuba diving or other risky activities.

Toting medication. Take an extra supply, and pack one in your carry-on bag and the other in checked bags, says Priscilla O'Reilly, of Grand Circle Travel, which specializes in travel for those 50 and older.

In case you need to fill a prescription, Rovetch recommends carrying copies of the generic names of your medicines, because the brand names may be different overseas. Bring medicines in the original containers, with your name on the labels.

Also, take copies of your prescriptions. If you travel with needles or prescribed narcotics, having a doctor's letter explaining your medical needs will make it easier to get through security and customs.

If you carry more than three ounces of liquid medicines, you'll need to have them inspected by airport security. For the latest requirements, check with the Transportation Security Administration (www.tsa.gov, click "Our Travelers"; 866-289-9673).

If you get sick. The U.S. embassy or consulate can provide a list of local English-speaking doctors. Frommer advises getting a free directory of English-speaking doctors around the world from the nonprofit International Association for Medical Assistance to Travellers (www.iamat.org; 716-754-4883). There's also a clinic directory on the International Society of Travel Medicine Web site (www.istm.org).

Know your limits. Consider how strenuous your trip will be, such as how much walking you'll have to do or whether you'll be in high altitudes. "You don't want to be in a new city every single day," Frommer says. "That kind of tour is extremely fatiguing."

Rovetch, who's in his eighties, likes to stay at bed-and-breakfasts or small hotels. He makes sure that he books a room that doesn't require walking up more than one flight of stairs.

If you tire easily, ask for a wheelchair at a large airport. You can request one when making your plane reservations. Canes can come in handy, too, Rovetch says. "It's useful for walking, and it makes other people more considerate."