If you’re really burning up, or you have symptoms like headaches, cramps, nausea, or vomiting, don’t ignore them. Get to some place air-conditioned, get at least a liter of water and a pinch of salt into you, and start thinking about an emergency-room trip if you don’t feel a lot better very soon. If you are older or especially heat-sensitive, this section goes double for you. When it’s 103 degrees in Rome, take a taxi rather than walk two miles to the cathedral. Finally, there is a good reason for the tradition of siesta in Southern Europe. During the blazing hours of the afternoon, a cool room, a shady tree near a pond or fountain, or in the fountain itself, are all good places to be.

- Tap water in most European countries tastes like skunk urine. It may be safe, and it is safe everywhere in Western Europe except possibly southern Italy, but it still tastes terrible. Don’t trust water in Greece, Turkey, Morocco, Eastern Europe, and Russia. Bottled water is available cheaply everywhere, although it will often be carbonated. To tell the difference, if you can’t read the label, squeeze the bottle. Plastic botdes of carbonated water will feel harder than noncarbonated.

- Bring along some vitamin and mineral supplements, and (unlike me) take them regularly. Those in hard tablet form (not soft gel tabs) should be all right without refrigeration; call the number on the bot-de to be sure. Also, bring along a supply of any drugs you need, and the prescriptions as well, to satisfy inquiring border guards. Check with your pharmacist on any prescription drug refrigeration requirements.