The numerous processes of the human body are patterned on a day-night rhythm dependent on an inner biological clock. It should not be difficult to understand that changing one’s location quickly in either direction, west or east, tends to disturb this rhythm. On an intercontinental flight from Frankfurt to New York there is normally a time difference of six hours, and on a jet trip to Sydney, Australia, the difference is nine hours. How confusing when on arrival your already strenuous day of travel suddenly becomes six, eight or even more hours longer. Since the human body can only compensate (some say) for a two-hour difference a day, you can easily figure out how long it will take your inner clock to become properly regulated again. After your return home the entire procedure will take place again in reverse.

If you are dependent upon certain medication (for example, insulin or blood-thinning medicines) you must give particular attention to the conditioning factors of time difference. Discuss your travel plans with your doctor. He will be able to give you good advice. Other information can be obtained from the book entitled “Ärztlicher Ratgeber für Flugreisende” (Medical Counselor for Plane Passengers [in German only]) by Dr. H. Baark, who discusses these problems thoroughly in a chapter called “The Proper Time for Taking Medicines in Intercontinental Flight.”

Health Takes Precedence

You may feel “fit as a fiddle” and have no thought of getting sick on your trip. But since you can never rule out the possibility, take reasonable precautions to keep the risk at a minimum. An upset stomach or digestive system can certainly dampen your joy while you are traveling.

An article by Dr. P. Wright, “Traveling in Good Health,” appearing in the Reader’s Digest, issue of June 1968, had the following to say about this complex subject: “99 percent of the cases of diarrhea are caused by water or food contaminated by bacteria, protozoa or viruses. Most hotels will serve bottled water on request. . . . Avoid putting ice in your drinks. . . . Also, use only safe water for brushing your teeth.”

Don’t take it for granted that health regulations in all places will meet up to the standards of your own country. In the Mediterranean area, the Near East, in tropical and subtropical countries, it is imperative to exercise caution when enjoying the customary dishes of the country. Don’t be too generous in “surprising” your digestive system. Avoid salads and raw vegetables, as well as raw meat, if possible. Forgo tasty treats made from milk or cream products if there is any doubt that they have been stored or cooled properly.

Tips for Hot Countries

Remember that when visiting hot countries you can do yourself much harm by being careless. For example, if you leave a European winter in January or February and arrive in the midst of a South American summer, be especially careful. Otherwise the change may be so sudden that, paradoxical as it may sound, your stay in the tropics may well begin with a bad case of the sniffles. Enjoy the sun in small doses, at least until your body has adjusted. If you perspire a great deal, do not neglect to eat enough salt with your meals. Also remember the increased risk of skin infection in hot countries.

In tropical lands your clothing should be of absorbent materials. This should especially be true of underwear. Also shirts, blouses or dresses should not hinder perspiration. Cottons and linens are the best. If possible, change underwear twice a day and make sure that your other clothing is comfortable, lightweight and easily washable. If at all possible wear shoes with leather soles and do not forget to take along a wide-brimmed hat.

Observing for your own benefit health regulations and advice (smallpox, cholera and yellow-fever vaccinations and preventive medicine against malaria and typhoid).

Taking out necessary travel insurance (health insurance in a foreign country, luggage insurance).