See also: Physical fitness

Regardless of where you plan on travelling, you are more likely to stay healthy if you are already living a healthy lifestyle. Getting regular aerobic exercise increases your endurance, enabling you to do more walking, hiking, swimming, skiing, or other more or less strenuous activities you may want to partake in on your trip, and making it less likely that a tough climb will result in a heart attack, dizziness, or shortness of breath.

Get any required or recommended vaccinations, starting 8 weeks before travelling, especially when travelling abroad to tropical or developing countries. If you are travelling to a particularly disease prone area, you may want to discuss immunoglobulin injections, which will make you immune to a host of diseases for several months. Consult a doctor to identify exact needs, as it depends on the case and the individual. For info about specific vaccines, see the article on infectious diseases.

Don't wait till the last minute, as some vaccinations take weeks to produce immunity and if you need multiple vaccinations, chances are good that some of them require a few weeks (usually 2 to 4) before the next vaccination. It really could be the difference between life and death. Also be aware that some countries require immunizations for travellers entering the country, particularly in areas where yellow fever is a risk. The internationally recognized "Carte Jaune" (yellow card) is a document created by the World Health Organization that is valid proof of immunization for yellow fever. Your doctor can either provide you with a Carte Jaune or update your existing card when you receive an immunization. Customs agents may check this record before allowing entry into a country.

Yellow fever vaccination is not the only potential required vaccination. For instance, travelers are not permitted to visit Mecca during Hajj without a meningococcal meningitis vaccine due to previous outbreaks that have occurred during that pilgrimage.

See also: Medication

If you have a pre-existing health condition, consult your healthcare provider beforehand. You may need to take special precautions when traveling.

If you use prescription medication, make sure to bring it with you, especially if it would be hard to find where you're going. If you will be away for more than the number of days remaining of the medication, talk to your pharmacist about getting an extra supply for your vacation. Also take non-prescription medication with you: some medications that are over the counter in one country require a prescription in another. Some drugs may be difficult or impossible to find in some countries.

However, make sure that by taking such medications on your trip, you won't run afoul of local drug laws and get in trouble. If crossing an international border, confirm in advance that you can convey your medications. What's legal in your home country may be illegal in another. In particular, always check for:

• narcotics, such as codeine-based cough syrup and medications for treating pain, such as Vicodin, Percocet, and oxycodone;
• benzodiazepines, barbiturates and other psychotropic drugs, such as phenobarbital for epilepsy, dronabinol for nausea, and some sleeping pills; and
• amphetamines, such as the anti-ADHD drugs Adderall and Ritalin (methylphenidate), especially when going to Japan.

Pay particular attention to medications if you are traveling to, or could be diverted to or involuntarily delayed in, United Arab Emirates. They restrict or ban a wide variety of medications, such as anti-diarrhea drugs, antidepressants, cough medicines, and hormone therapy (including estrogen and testosterone) and painkillers, and the mandatory prison sentence for even trace amounts of a banned substance is four years. The UAE also treats common foods that contain poppy seeds with the same harsh sentence as smuggling pure heroin.

Singapore is also notorious for its strict anti-drug policies and for executing drug users. Unlike the UAE, they provide a comprehensive list of prescription medications that you must seek permission to possess for personal use, and a lengthy list of drugs that are illegal under all circumstances, including nicotine gum and any chewing gum that claims to promote dental health. Note that the presence of cannabis in a urine test has been counted as "possession" in Singapore, even if it's certain that the traveler used the drug in another country.

Take copies of your prescriptions in case you lose or run out of medications or to prove the medication is for your personal use.

If you are traveling within your own country or another country that has an agreement with yours, you may be able to have a prescription temporarily transferred to a local pharmacy. Ask your pharmacist if this is possible in your case.

Also, there are some diseases that can be prevented with prophylactic medications, including malaria. As with vaccinations, it can take weeks for immunity to build up, so find out well in advance of your trip which medication(s) you need and when you should start taking them. To be effective malaria medicines must be taken for a period of time after exiting area at risk, which can range from days to weeks, so it is important to keep that in mind as well.

Especially if you are going to be doing hard hiking in remote areas, make sure you bring a first aid kit with you, including a tourniquet. You don't want to be caught without in an extreme situation.

Take a health kit of medications and first aid items. Ensure that the quantity of prescription medications, and other items that may be difficult to obtain while travelling, will last for the entire trip. If you're taking it as hand luggage on a flight, be sure to leave the scissors out though.

If there is any chance you might have sex on your trip, buy the condoms of your choice and take them with you. If you don't, there's a risk that you could get carried away by the moment and catch something you can never get rid of, get pregnant or get someone pregnant. Also, condoms sold in some places may be the wrong size for you or may be poorly quality-controlled and liable to break. And while it has become extremely rare, there are some places in the world where condoms are hard to get, if not impossible.

Being of a very durable, cheap and lightweight material, condoms can in a pinch also serve purposes other than the one for which they were designed. In fact, some military units regularly carry condoms for non-sexual uses. Condoms can serve as makeshift waterproofing or as containers for up to a liter of liquids or some solid substances. Do keep in mind that condoms will not survive contact with any sharp objects and are liable to break under UV radiation or extreme temperatures; use things that were actually designed to do the job instead of condoms if they are available.

Main article: Travel insurance

Verify what your regular or credit card insurance will cover while away from home, and consider taking out travel insurance to cover any difference. Although travel insurance for lost luggage and delays will save some small costs or inconvenience, the cost of medical treatment or medical evacuation can be crippling if not covered by insurance. In some countries, an inability to show you are insured or can otherwise pay may lead to your being refused treatment altogether. Some countries will not allow entry into the country without proof of medical insurance, such as Cuba. Worst case scenario, you pay for it and never use it. So you cost yourself a few bucks. But if you need it and don't have it, the downside is massive.

Whether you are in a car or a plane, you are well-advised to use a seatbelt and to check everybody else is. You don't want your child from the back seat to hit you in 70 km/h, neither do you want to crash through the windshield. Also anything borderline hard or heavy should be packed so that it stays where it is in case of an accident; you don't want a bag or flashlight in the back of your head.

If you are on any kind of bike, make sure to wear a good helmet, and if you are going somewhere where helmets are hard to find, consider bringing one from home. You do not want to have your vacation spoiled by an easily preventable brain injury.

Keeping clean is usually easy if you stay and eat at a business hotel. In a low-income country or in outdoor life, it is more of a challenge. Toilets are a risk factor.

See also: Dangerous animals

We have a separate article on this topic, but the watchword really is to respect animals, listen to what local people say about them, and use common sense.

In the event that you have potentially been exposed to rabies, prompt treatment is critical. Treatment only works prior to development of symptoms and rabies is nearly always fatal once symptoms develop. More on rabies can be found under the article for infectious diseases.

Main article: Water safety

Some beaches are extremely dangerous. If you ask some locals where the beach is, and they point you in its direction but tell you not to swim there because there are evil spirits in the water, don't ignore their advice. Whether you call it evil spirits or undertow, it will kill you just as dead. A word to the wise is, if you are considering swimming at a remote ocean beach with no lifeguard, make sure it is partially enclosed by a cape, because that is likely to cut off some of the riptide. Of course, it's much safer not to swim unless a lifeguard is on duty.

Also be careful in places where dangerous jellyfish are endemic. Jellyfish attacks are much more frequent than shark attacks, and from some species, more likely to be fatal.

There is no reason to be paranoid about risks involved with swimming; just know what the risks are in each place you visit and make a judgment about them.

In terms of diving risks, scuba diving can easily be fatal if you are not properly trained. Fortunately, you generally cannot scuba dive unless you are properly trained and certified, which minimizes the risks greatly.

If you would prefer to stay closer to the surface of the water, snorkeling can be a good alternative. It contains its own risks, but in many places, you can stay in shallow water, where you can swim back to shore more quickly and may even be able to stand up if you have to (though it is bad to stand on fragile coral reefs and should be avoided whenever possible).

At some beaches algal bloom is a recurring problem. If the water has a layer with an odd colour, check whether this is normal or may be harmful.

Swimming or wading in fresh water, in some warmer climate countries, may lead to parasitic infection. For instance, around 200 million people are infected worldwide with schistosomiasis, a parasitic worm found in fresh water. Where this is a risk, the effective protection is to not enter the water. Consult a travel medicine specialist for advice for where this is a risk.