(CNN) -- Explorers used to plan their expeditions for years. They stockpiled supplies, mapped their routes and hired experts to ensure a safe journey.
But today, travelers often jump on a plane with barely a thought about their well-being.
"Don't assume it's going to be OK," said Dr. Deborah Mills, author of "Travelling Well" and spokeswoman for the Australian Travel Medicine Alliance. "You plan for your passport, your visas and you save your money, but health should be on your little checklist."
Getting sick overseas can be scary. You're in an unfamiliar place and often don't speak the language. Although each trip is different, there are universal things you can do to keep safe.
Here are five ways to stay healthy while traveling abroad, whether you're exploring new territory or not.
1. Be prepared
The first step is to register with STEP, says Brendan O'Brien, director of American Citizens Services with the U.S. State Department. The Smart Traveler Enrollment Program asks for information about your trip so the U.S. government can send alerts for the country you're visiting and is better able to assist you in an emergency.
The World Health Organization is also an excellent resource for researching your destination. The WHO International Travel and Health guide provides information on the health risks associated with each country and what you can do to prepare.
Most important is to schedule a visit with a doctor who specializes in travel or the area you're visiting at least four weeks before your departure, says WHO public health expert Dr. Gilles Poumerol.
A travel doctor will be able to give you the required and recommended vaccinations as well as discuss any medical issues you may encounter abroad.
2. Get insurance
"In many countries where you have limited access to health care, good health care is only found in the private sector and can be very expensive," Poumerol said.
Plus, in an emergency, O'Brien says, evacuation to the United States can cost more than $50,000.
Ask your health insurance company whether your policy applies overseas and whether it will cover trips to a foreign hospital. If not, there are many companies that offer short-term travel health insurance for a reasonable fee, O'Brien says. A list can be found on the U.S. State Department's travel website.
3. Pack well
As much as you might want to take that extra pair of shoes, you should leave room in your carry-on bag for some important medical documents and supplies.
Mills recommends packing a medical kit that includes extra doses of any regular medications you take, antibiotics, sterile syringes/needles and the basics for first aid: bandages, wraps, ibuprofen etc.
"You won't get the sort of things you need in a regular drugstore," she said, so asking your travel doctor for supplies is best.
Poumerol also suggests bringing a note from your doctor in English and the language of the country you're visiting that justifies any medication you're bringing on the trip; some countries outlaw certain drugs that are legal in the United States. Other experts recommend bringing a note about any medical equipment that could be ruined by airport scanners.
Packing an emergency contact list is important, O'Brien says. Contacts should include the local embassy and/or consulate, relatives who should be notified if you get sick and your health insurance company.
4. Don't wait
Mills' travel medicine clinics have helped people plan trips abroad for years. The top four medical issues her patients deal with are gastrointestinal problems, respiratory illnesses (coughs, colds, pneumonia), pain and wounds (cuts, scrapes, bruises).
But of most concern, she says, are tropical diseases like malaria. ''We call malaria a 'cliff disease.' People don't really feel too bad, and then all of a sudden they're over the cliff, and they're dead."
Even common stomach problems caused by drinking or eating local fare can rapidly deteriorate into severe dehydration, Mills says.
If you are feeling sick in a foreign country, seek help as soon as possible. Ask your hotel concierge for good health care facilities nearby. Your travel health insurance company and the embassy will also have a list of local providers who speak your language.
5. Be aware
You have to be in charge of your health. If you're being treated abroad, question the medical staff about their sterilization practices; Gilles says injection equipment should be put in boiling water for at least 30 minutes or used only once. Also be sure doctors and nurses are wearing gloves to prevent fluid transfer.
Limiting your alcohol intake will keep you focused on your safety, Mills says. If your common sense is intact, the rest of your body should follow.