Yosemite National Park ranges in elevation from 2,000 feet to over 13,000 feet. Yosemite Valley, the most visited area of the park, sits at 4,000 feet and Tuolumne Meadows, one of my favorite areas of the park, is around 8,600 feet. Higher altitude means thinner air (less oxygen in the air). This makes it harder to breathe, and your heart rate increases in order to pump more oxygen through your body. It is easier to become dehydrated at higher elevations because your body is working harder to produce extra red blood cells to get you the oxygen it needs. If you fly to Yosemite, you should drink extra water on the plane, as air travel tends to dehydrate. On top of that, if you live in a more humid environment you should know that Yosemite’s humidity in the summer is almost non-existent– like 12%. You need to give yourself a day or two to acclimate and hydrate before attempting any moderate or strenuous hikes.
Learn From My Mistakes: Acute Mountain Sickness
In the summer of 2013 my family and I flew from a humid (80%), low elevation (28 feet above sea level) environment to Yosemite for camping and backpacking. I failed to drink enough water on the plane, so by the time we arrived in Yosemite Valley I was already dehydrated and could immediately feel my heart beating faster and my breathing harder from just walking around.
We spent just one night in the valley before taking the hiker’s bus to Tuolumne Meadows. That same day we hiked to the top of Pothole Dome, which is considered an easy-moderate short hike. Once again, I didn’t drink enough water. That night in our tent, my heart raced every time I moved, I felt slightly nauseated, my nose was terribly dry because of the ultra-low humidity, and I was very dehydrated. I knew I had to re-hydrate the next day to prepare for our backpacking trip so I made myself drink tons of water, and I found my new best friend– coconut water– at the Tuolumne Store. I was not able, however, to find saline spray for my nose and I deeply regretted not packing any. By that evening, after a day of easy hiking and drowning myself in water & coconut water, I felt back to normal.
Acute Mountain Sickness can happen to anyone– even Olympic Athletes. And it can progress to High Altitude Pulmonary Edema or High Altitude Cerebral Edema (more likely over 13,00 feet but can happen at 10,000), which are both potentially FATAL. Remember: your child might not know exactly how to describe why he/she feels bad, so be aware of the signs of AMS in children. Take care of yourselves out there!
Every time I go to Yosemite I forget just how dry it is. The trails are powdery dust. There is no humidity, and rain is exceptionally rare in summer. It’s hard to drink the amount of water you need to stay hydrated. Even though these discomforts take a backseat to Yosemite’s immense beauty, I will never again forget to pack a few essential items for basic creature comfort!
Here is a list of Comfort Essentials (Be certain to store these properly when not in use!):
- Saline spray for your nose
- Lip balm
- Small tube of hand lotion, unscented
- Sun hat
- Non-water options:
- Coconut water (readily available at all Yosemite stores)
- Vitalyte drink mix (This is my personal favorite electrolyte drink mix and I don’t remember if you can get it in the park– I take my own– but there are other electrolyte drinks available.)