ON THE TRAIL
Stay hydrated. You know this, but every year dozens of hikers get into trouble.
1. Store water in multiple containers, so you can never lose your entire supply.
2. Keep water accessible and sip often.
3. Use drink mixes (like CamelBak’s Elixir tablets; $10, camelbak.com), to replace the electrolytes you lose through sweat.
4. Shoot for at least one liter of liquid per hour; your urine should be clear.
5. Eat salty snacks to avoid dangerously low sodium levels, a condition called hyponatremia caused by overhydration.
Hike north. Plan your route so the sun is generally at your back. Your pack will absorb heat instead of you.
Adjust your schedule. Start before dawn to take advantage of the coolest time of day (after sunset, heat from the day still lingers). Get your miles done before noon, or take a long lunch layover in the shade and continue hiking after dusk. "There’s a reason why people all over the tropics take siestas during the hottest part of the day," notes Bruce Smithhammer, a veteran NOLS instructor in Mexico. If you’re climbing out of a canyon, time your ascent so that the trail will be shaded. Note: Avoid night hiking in rattlesnake habitat; they come out when the temperature cools.
Shade your legs. Sun at your back? Hang a shirt from the bottom of your pack so that it shields your legs.
Air out your feet. Take off your boots and socks during rest breaks.
Protect your head. If you don’t wear a hat (or opt for a visor), put sunscreen in the part of your hair.
Eat light. Your appetite might decrease in hot temps, but you still need fuel. Replace greasy summer sausage with a chicken pouch, and have smaller, more frequent meals.