Dusseldorf, Germany  - Vacation is supposed to be the best time of the year, with carefree hours spent on the beach, in the mountains or whichever locale sparks the vacationer's interest.

But an unexpected illness can quickly put an end to the fun.

"Sunburn, mosquito bites and diarrhoea are the three most common problems vacationers have to fight," says Tomas Jelinek, head of the Centre for Travel Medicine in Dusseldorf, Germany. But proper preparation and taking steps to learn about your travel destination can go a long way to making sure you stay healthy while on vacation.

PREPARATION: According to Jelinek, travel luggage needs to be fully outfitted with insect protection and a "potent sunscreen," i. e. a product with a high sunlight protection factor, plus UV-A/B protection.

"Often when they travel to the tropics for the first time, Europeans completely underestimate the sun." Don't forget to take clothing appropriate for the climate.

To avoid diarrhoea, follow the old rule - cook it, peel it or leave it. In other words, make sure all food has been shelled and/or fully cooked before eating.

TRAVEL PHARMACY: Regardless of your destination, a small selection of medicines should always come with you on vacation. Jelinek says this travelling pharmacy should include remedies against nausea, diarrhoea and malaria, plus a basic painkiller.

The pharmacy should not contain any blood-thinning products containing aspirin. "Dengue fever is widespread in tropical and subtropical regions. It can cause blood thinning, plus splitting headaches and pain in the extremities," says Jelinek. Products with aspirin only make the symptoms worse.

"More and more, this is why we recommend packing antibiotics," adds Jelinek. Counterfeit drugs circulate in many underdeveloped countries in Asia and Africa, meaning a sick person can never be certain if he's getting the medicine he really needs in an emergency.

PRESCRIPTIONS: Chronically ill people need to take care of themselves while on vacation. People travelling with prescriptions can generally take certain amounts of medications for personal use. Within large parts of Europe, a doctor's certification, certified by a local authority, should be kept with the medicine while travelling.

To prevent any problems, it's recommended to get the prescription and certification in English, including information on dosages, active ingredients and the length of the trip. This should make it easier for foreign officials to check if the amounts of medicine are appropriate for the length of the trip. Some countries' medical authorities offer prepared blank pages on their websites to print out.

DOCTOR'S VISITS: "You don't go to the doctor in a foreign country with a simple toothache," says Simone Meisel of the Consumer Central in the German state of Sachsen-Anhalt. But, if the pain turns acute, then it is time to hunt down a doctor.

Jelinek says a long-persisting fever, extreme exhaustion, skin ulcers or bloody diarrhoea are all signs that it's time to go to the doctor. For comparison's sake, regular diarrhoea goes away all by itself after three or four days.

European citizens travelling within Europe should have a European health insurance card with them while on their vacation. If you do end up at a doctor's office, demand a formal bill. "It has to say which medical services were rendered," says Meisel, who points out that a proper receipt will help when it comes time to seek reimbursement from a health insurance agency back home.

However, insurance companies generally only pay for services for which they would provide coverage domestically.

But that's not the only reason to get traveller's insurance, says Meisel. It can also help with a medical transport, which often won't be covered by standard insurance, "especially not if the medical care could be provided on site."

To truly take care of yourself, don't just make sure you're provided for medical transport home, but for practical medical care or treatments that last longer than 14 days. (dpa)