Staying hydrated is essential to peak performance and climbing enjoyment, dehydration can cause lagging pace, apathy, headaches, fatigue, and can affect decision making. Constriction of blood vessels due to dehydration makes you susceptible to hypothermia, frostbite, and altitude sickness.
Most athletes understand the importance of hydration but many climbers still end up mildly dehydrated without realizing it. Especially since some of the symptoms of altitude sickness are similar to those of dehydration.
Start hydrating the night before your climb and continue by bringing an extra water bottle for the car trip to the trailhead and one for the ride home. One hydration measure is having to stop to urinate on a two hr drive to the mountain, then again shortly after leaving the trailhead, and every hour or two on the way up to base camp. Aim for urine color clear enough to read through.
Hydration packs with tubes work best for staying hydrated but they also tend to freeze at night or higher elevations. On a typical climb like Rainier I’ll balance ease of hydrating with insurance against freezing by carrying a 2 liter Platypus (with tube) and full 1 liter nagaline. The nagaline also provides a backup in the event of Platypus getting punctured
The bladder type water storage units such as platypuses can also be used in emergencies to melt snow using body heat if you run out of fuel. Here are ten rules for managing your hydration:
1. The average climber should aim for 4-5 liters per day.
2. If you expect the temperature to go below freezing take steps to prevent your water from freezing, like keeping it close to your body (shouldn't touch bare skin) and storing your container upside down (water freezes from top down, if it does freeze you'll still have access through most of your water through the top), bury in 2ft of snow on all sides (mark and know the location well), or melt snow just before departing for the summit.
3. Some climbers recommend filling Nagaline bottles with warm water and sleeping with to keep warm. I’ve found it works great to warm up cold feet.
4. Bring a water filter to conserve fuel, you can fill up on way up or and pump through filter rather than bringing to boil.
5. Bring it to a rolling boil. Most experts recommend 10 min but studies have shown 99% of organisim will die within 60 seconds of a rolling boil. Use your judgement since fuel could be limited.
6. Carry Iodine tablets for emergencies below tree line.
7. Sip don’t gulp, especially if your feeling quezzy
8. Occasionally flavor with Gatorade/powdered drink too much can make you sick.
9. Caffeine, Diamox, etc, requires extra water.
10. Keep your water bottles clean. Lemon wedges or drops work good for field applications.