Those with medical conditions may want to obtain a Medic Alert membership , which includes a stainless steel ID tag, among other bene- fits, like a 24hr. collect-call number. Contact the Medic Alert Foundation, 2323 Colorado Ave., Turlock, CA 95382, USA . ONCE IN ISRAEL ENVIRONMENTAL HAZARDS The geographic diversity in Israel is extraordinary, and the environmental risks are correspondingly broad. The most common health problems are related to the heat, particularly in the desert. Heat exhaustion and dehydration: Heat exhaustion, characterized by dehydration and salt deficiency, can lead to fatigue, headaches, and wooziness. Drink plenty of fluids , eat salty foods , and avoid dehydrating beverages . Wear a hat, sunglasses, and a lightweight longsleeve shirt in hot sun. Continuous heat stress can eventually lead to heatstroke, character- ized by a rising temperature, severe headache, and cessation of sweating. Vic- tims should be cooled off with wet towels and taken to a doctor. Sunburn: Wear plenty of sunscreen, preferably SPF 15 or higher. If you're head- ing toward the Negev or Golan, particularly hiking, buy sunscreen in the city and bring it with you. Apply it liberally and often to avoid burns and to reduce the risk of skin cancer. If you are planning on spending time near water or in the desert, you are at risk of getting burned, even through clouds. Remember to slather the tops of your feet, which are exposed to the sun all day. Protect your eyes with good sunglasses, since ultraviolet rays can damage the retina of the eye. If you get sunburned, drink more fluids than usual and apply Calamine or an aloe-based lotion. PREVENTING DISEASE INSECT-BORNE DISEASES Many diseases are transmitted by insects-mainly mosquitoes, fleas, ticks, and lice. Be aware of insects in wet or forested areas, especially while hiking and camping. Mosquitoes are most active from dusk to dawn. Wear long pants and long sleeves, tuck your pants into your socks, and buy a mosquito net. Use insect repellents, such as DEET, and soak or spray your gear with permethrin . Consider natural repellents that make you smelly to insects, like vitamin B-12 or garlic pills. To stop the itch after being bitten, try Calamine lotion or topical cortisones , or take a bath with a half-cup of baking soda or oatmeal. Ticks-responsible for Lyme and other diseases-can be particularly dangerous in forested regions. Pause peri- odically to brush off ticks using a fine-toothed comb on your neck and scalp. Do not try to remove ticks by burning them or coating them with nail polish remover or petroleum jelly. FOOD- AND WATER-BORNE DISEASES Prevention is the best cure: be sure that everything you eat is cooked properly and that the water you drink is clean. Tap water is generally safe for drinking in Israel. If you need to drink water from nature, purify it first by bringing it to a rolling boil or treating it with iodine tablets, available at any camping goods store.