Two cases involving possible food poisoning among tourists have raised concerns about what travelers can do to prevent and treat food-borne illnesses — not just during off-the-beaten-path adventures, but in and around resorts.

While the cause of the recent death of Miller Gardner, the 14-year-old son of the former New York Yankees outfielder Brett Gardner, has not been confirmed, Miller, along with other members of the Gardner family, is reported to have experienced gastrointestinal distress after eating a meal while on vacation in Costa Rica. And a lawsuit filed this year in Toronto in connection with the food poisoning-related deaths in 2023 of 8-year-old Stephen Gougeon and his mother, April, alleges, among other things, that the Dominican Republic resort where they stayed did not take sufficient care in food handling.

In general, gastrointestinal illnesses among tourists — travelers’ diarrhea and food poisoning — is especially likely to occur in countries where the water supply is unsafe. But there are also many cases of food poisoning, and hundreds of deaths, in the United States every year, and these infections can occur anywhere there are lapses in how food is handled. Raw or undercooked meat, fish and shellfish can be contaminated, and the Centers for Disease Control and Prevention’s list of high-risk foods includes raw eggs and unpasteurized milk.

Travel presents additional concerns. “People may be in places where the tap water is not necessarily safe, and they don’t have control over how food is prepared or handled,” said Dr. Adam Ratner, director of the division of pediatric infectious diseases at Hassenfeld Children’s Hospital at NYU Langone in New York. “When you’re home, you have some control, and you have U.S. and local health department standards. It can be harder to assess safety somewhere else.”

Parents should be especially vigilant. Babies and young children are vulnerable to dehydration, which is generally the most dangerous aspect of gastrointestinal illnesses; other groups at high risk include pregnant women, older people and anyone who is immunocompromised. But even younger adults and adolescents may not realize how serious the symptoms of food poisoning can be, and when it is important to get medical help.

Here’s what you need to know to be prepared when traveling, and what to do if you suspect that you or your travel companions have food poisoning.

What is food poisoning?

Food poisoning means you’ve eaten something that is contaminated, most often with bacteria and the toxins they produce, but sometimes with a virus or a protozoan parasite. It can happen because the food wasn’t thoroughly cooked, or because it became contaminated after being cooked. In other words, the problem can arise at any point while food is being prepared, handled and served.

When members of a group who ate together get sick at the same time, that’s usually evidence of food poisoning. The typical symptoms are diarrhea and vomiting, sometimes accompanied by fever, chills and abdominal pain. With some contaminants, especially certain bacterial toxins, people get sick within a couple of hours, while with others it can take 24 hours or so.

The biggest danger is fluid loss and dehydration. However, some bacterial toxins can do other kinds of damage to the body, and there are some bacteria that can actually produce a general infection, or sepsis, especially salmonella.

What foods should you avoid on vacation?

Stay with food that has been thoroughly cooked and served hot. Avoid raw shellfish, which may have come from contaminated water, and raw or undercooked meat. Especially in countries where the water supply isn’t safe, avoid precut fruits and salads, which may have been washed in that water. The C.D.C. also warns against foods like salsas and ceviches, which contain raw ingredients.

Basically, food is safest when it’s thoroughly cooked and served hot. That means buffets can be problematic, with food often standing for long periods. If you do eat at a buffet, the hot food should be truly hot, and if there is cold food, it should be truly refrigerated; nothing should be approaching room temperature.

If food has been cooked and then allowed to sit around — as is often the case with street food — stay away.

Be suspicious of ice — boiling kills potential pathogens, but freezing does not. If the ice is made from contaminated water, it isn’t safe. If you have concerns, stick to bottled drinks from the refrigerator.

Any shots you should get before you travel?

Everyone should be immunized against hepatitis A, a virus that is a common cause of gastrointestinal illness in many parts of the world. Children are routinely immunized against hepatitis A in infancy now, but check that adolescents have had the vaccine — and adults should get it if they haven’t had it.

What should you take with you?

You can travel with packets of oral rehydration solution — basically a combination of sugar, salt and potassium that can be mixed with clean water and drunk to replenish fluids and electrolytes.

Some doctors will prescribe antibiotics to carry with you. The idea is to take the antibiotics if you develop diarrhea, hoping to shorten the course of the disease. However, having the antibiotics — or even taking them — should not make you cavalier about symptoms; you still need to get medical attention if you’re seriously ill.

For parents, it’s worth talking with your child’s pediatrician about how to be in touch from abroad if you have concerns, and you should look into insurance coverage while traveling. You might also want to research in advance how to find medical help in your destination — whether that means knowing the location of the nearest hospital or the emergency phone number. It may be helpful to refer to the International Society of Travel Medicine’s global clinic directory.

What should you do if you develop symptoms?

Above all, stay hydrated. Drink sports drinks; sip clean water, broth or tea; and use your oral rehydration solution.

Take the illness seriously. If there are repeated episodes of vomiting and diarrhea, if you truly can’t keep anything down, and particularly if things are getting worse, don’t wait to seek medical attention. You should be especially concerned if fever, chills, bloody diarrhea or severe abdominal pain develop.

With a younger child, dehydration can happen quickly — over a matter of hours — and it can be difficult to get a sick young child to drink. The American Academy of Pediatrics advises contacting a doctor promptly if a child is not drinking.

Most likely, especially at a resort, you will find yourself going through your hotel to find medical help. The most important advice is that if you are concerned you need to be willing to insist on medical attention, and if necessary, go to a local clinic or hospital. “Don’t take no for an answer,” Dr. Ratner said.

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