March 24, 2019
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Travel Safely in Hot Weather

by Jeanine Barone  

For many people, vacation means going somewhere warm, and indeed many of the world’s most enchanting destinations are also some of its hottest (sometimes year-round). An enjoyable trip can quickly turn uncomfortable or even dangerous if the temperature or humidity soar and you’re not properly prepared. Whether you're headed to Bangkok, Bahrain, or Brazil, here are some tips to help you travel safely in hot climes.

Wear the right clothing. Opt for lightweight, light-colored wickable clothing that is loose-fitting (and a lightweight, wickable hat, if you wear one). The term "wickable" means that the fabric transfers your sweat away from your skin so it can evaporate. Wickable fabrics are usually synthetic, though not always; you may be surprised to learn that thin Merino wool garments are wickable and light enough to wear in hot weather. Many large sporting goods stores and manufacturers of performance wear sell special clothing that’s advertised as keeping the wearer cool and dry when exercising in the heat. But studies that have tested the performance of such fabrics have been largely inconclusive, according to a review article in the journal Sports Medicine. So your best bet is to choose a fabric that you find comfortable and see how it works for you.

Cool your head and neck. Wear a cool wet towel, bandana, or neck gaiter (often called a buff) around your neck if you want. It probably won’t lower your core body temperature but it may feel good in the heat. Don't bother with special micro-fiber "cooling" towels, which you may have seen athletes—including Serena Williams—wearing after a workout. You wet the towels, wring them out, and snap them to activate the proprietary cooling mechanism. But when Consumer Reports tested two such synthetic-fabric products against a plain wet cotton dishtowel, it found that all three towels cooled down to about the same temperature as a result of simple evaporation. (The test didn't look at whether any of the products reduced core body temperature.)

Don’t forget the sunblock. Bright, sunny skies often go hand-in-hand with hot temperatures. Whether you are sitting on a beach, having an active adventure on the water or in the mountains, or touring a city, be sure to apply broad-spectrum sunscreen with an SPF of 15 or higher (30 or higher if you’re very sun-sensitive or have had skin cancer). And don’t forget to carry it with you, because you will need to reapply it during the day as you sweat or get wet.

Stay hydrated. It's important to drink lots of water in hot weather, but don’t make the mistake of waiting until you're thirsty. Keep yourself hydrated during the day by taking small drinks throughout. You can carry a water bottle in your bag or backpack or use hands-free hydration systems, which are similar to backpacks. (Camelbak is one popular brand.) These packs have a built-in water reservoir bag connected to a long tube (some tubes and reservoirs are insulated) that remains easily accessible to your mouth. Whether you're walking on city streets, navigating a trail, jogging, or bicycling, all you have to do is bite on the tip of the hose to open the slit and then suck up the refreshingly cool water as you would from a straw.

Don’t count on a handheld fan. It may seem like an easy heat-relief solution, but the CDC and the EPA both recommend against relying on a fan as the only way to keep cool. A fan won't prevent heat-related illness if the temperature is in the upper 90s or higher; it just recirculates hot air and may give a false sense of coolness. A better bet is staying in air-conditioned rooms or taking a cool shower or bath.

Stay out of the sun during the hottest portion of the day. In most places, that’s from about noon to 3 p.m. Staying indoors or in the shade lessens your chances of overheating. Take refuge in an air-conditioned room, tour a museum, sit in the shade, take a long lunch in a restaurant, or do any other activity that keeps you out of the sun.

Drink a slushy drink. Researchers have found that crushed ice is better than cold liquids alone for lowering core body temperature, most likely because the crushed ice is better at absorbing heat from the gastrointestinal tract. But the best results may come from combining a slushy beverage with other, external cooling methods. In a study in the Scandinavian Journal of Medicine & Science in Sports, researchers compared two cooling strategies in men who were about to exercise intensely in the heat. One strategy used several external techniques at once, including cold, wet towels on the neck and immersing an arm in cold water. This was compared with internal cooling by drinking a slushy (called a slurry in some countries). Although both regimens worked similarly in terms of lowering core body temperature, cooling the neck and other body parts had a longer-lasting effect. So if it’s really hot, try placing a cool towel on your neck while you drink the slushy beverage.

Protect against mosquitoes. They’re prevalent in tropical climates and can spread diseases including malaria, dengue, and Zika. To avoid getting bitten, stay away from standing water whenever possible, wear long-sleeve shirts and long pants, especially at dusk, and apply insect repellent to exposed skin. For more information, see How to Prevent Mosquito Bites.

If you feel that you are overheating:

  • Immerse your hands or forearms in cold water for about 20 minutes. In a study in the Journal of Science and Medicine in Sport, subjects who immersed both hands in a specially designed hand-cooling device for 20 minutes after exercising in the heat significantly reduced their core body temperature.
  • If you experience symptoms of heat-related illness—which often starts with muscle cramps and can progress to weakness, rapid and faint pulse, pale and clammy skin, nausea, vomiting, and other symptoms—the CDC advises moving to a cooler location immediately, lying down and loosening your clothing, applying cool, wet cloths to your body, and sipping water.
  • Seek medical help if you can’t stop vomiting or if you (or a person you are traveling with) experience any of these signs of heat stroke.

Also see 8 Ways to Avoid Foodborne Illness When Traveling.