By Laura Landro

It’s the worst-case scenario for even the most intrepid traveler: a medical emergency or health crisis in a foreign country.

Though many travelers take important steps against infectious disease, including vaccinations, malaria pills and diarrhea remedies, experts say they often overlook other physical dangers: sudden catastrophic illness, accident, assault or natural disaster such as the recent earthquakes in popular tourist destination Nepal. Terrorist attacks and civil unrest in major foreign capitals add another level of uncertainty to vacation planning.

“Everyone thinks the most likely reason they are going to die on a trip is infectious disease,” says Frank James, a physician and clinical assistant professor. But in fact, he notes, more likely causes of death include being the victim of violent crime, being struck by a motor vehicle, or having a heart attack or a stroke.

While it isn’t always possible to anticipate every risk, travelers can take a number of steps to prepare for unexpected illness or injury, and new apps can quickly provide information about danger spots or link travelers to help.

Time for a checkup

For starters, Dr. James advises a pre-travel physical, especially for patients who are overweight or out of shape, noting that risks can be exacerbated by dehydration or overexertion on summer trips. He also advises against certain destinations for those at higher risk, such as a 70-year-old with a pacemaker.

“I tell people about once or twice a month—when their heart is set on doing something—that it isn’t safe for you to go for health reasons.” Rather than trekking around Madagascar, for example, he might recommend a cruise.

Overseas hospitals or clinics may not always be prepared for the highest level of care, and patients can get caught up in red tape or language barriers. It’s advisable to check if your health plan covers overseas medical treatment, and purchase additional coverage if not. Some companies provide on-the-spot medical care and transport from the point of illness or injury, back to the U.S. if necessary.

Robert Talley, a 68-year-old dentist from Norman, Okla., and his wife, Pamela, have been active travelers for years; trips have included mountain climbing and hunting in Africa. Dr. Talley says he never had a problem—until a trip to Turkey in December. While on a domestic flight there, he suffered an irregular heartbeat and other symptoms. After landing in Antalya, he was taken to a local emergency room, diagnosed with a type of stroke and told he would need to be hospitalized for two weeks.

Dr. Talley is a member of a Boston-based company that provides travel risk, crisis management and evacuation services for companies and individual travelers, and partners with hospitals for medical consultations. Pamela Talley contacted the company the day after Robert was hospitalized; They, in turn, contacted the hospital for copies of diagnostic scans and doctors’ recommendations. When some of its requests weren’t met, the company sent a critical-care paramedic to Antalya to coordinate care and get copies of the tests for review by cardiologists in the U.S.

A Turkish doctor wanted to keep Dr. Talley in the country for several weeks and then implant a pacemaker, but Dr. Talley wanted to return home. U.S. doctors felt he would be safe flying to the U.S. on a commercial flight in business class. A staffer coordinated his release and accompanied him on the four legs of the flight home, assisting with details and monitoring medications. He also arranged for transportation and admission to a heart and vascular Hospital in Dallas, where doctors decided a pacemaker wasn’t appropriate and implanted a heart-rhythm monitor that can be read remotely, according to Dr. Talley.

“You just don’t know when that freak event is going to happen,” says Dr. Talley, who adds that he plans to return to Turkey.

These memberships, based on trip length and the extent of services, start at $119 for a seven-day trip. (Destination isn’t a factor in pricing.) Annual memberships start at $329 for an individual and $579 for a family, with additional fees for security memberships that cover nonmedical emergencies such as natural disasters, terrorism and geopolitical instability. After the Nepal earthquake, the company had 125 requests for help from members, including some on mountain-climbing expeditions, according to chief executive officer Dan Richards.

Members can access an app, the Global Rescue Grid, searching by country for risk ratings based on both security and health.

Other companies offering travel evacuation and medical-assistance services include MedjetAssist and Medex, and insurance companies also offer various options.

Getting informed

The Centers for Disease Control and Prevention and the State Department offer free travel websites and apps to help travelers assess health and security risks. The CDC’s TravWell, aimed at consumers, includes destination-specific recommendations, checklists and packing lists. (For those worried mostly about adventurous eating, it also has an app that lets users search for health risks by country and food type, called Can I Eat This?) CDC’s Health Information for International Travel—also known as the Yellow Book (because of the color of its cover)—is primarily aimed at health professionals who advise patients about travel risks, but it can also help consumers.

The State Department offers Smart Traveler, an app with frequently updated country information, travel alerts, warnings, maps and U.S. embassy locations. It also provides access to the Smart Traveler Enrollment Program, a free service that enables U.S. citizens and nationals traveling abroad to enroll their trip with the nearest embassy or consulate, get information about safety conditions, help the embassy contact them in an emergency, or assist friends and family in getting in touch.

“You have to be prepared for anything when you travel,” says Paul Auerbach, a professor of surgery who edits a textbook on wilderness medicine and a packable paperback guide, which includes advice on dealing with natural calamities such as typhoons, earthquakes and tsunamis.

Dr. Auerbach, who recently returned from providing medical aid to locals in Nepal, offers some nonmedical advice as well: Always have extra copies of your passport stashed in different locations, keep important medications close, and carry an extra power supply to give your cell phone an extra charge should you not have access to electricity.