I took a group of 4 up to Horseshoe Meadows this past weekend for an over-nighter at Chicken Spring Lake. All of us had some (somewhat) surprising issues with the elevation. I have a few ideas about why this happened and am interested in what you guys think.
Background Info
Hiker A - no previous issues with AMS. Successfully hiked Whitney a year ago on an overnight trip, spending one night at the portal campground and a second night at Outpost Camp.
Hiker B - no previous issues with AMS. Successfully day-hiked Whitney a couple years ago with no acclimation period
Hiker C - history of 'AMS headaches*' whenever hiking above 11k
Hiker D (me) - history of 'AMS headaches*', suffered as low as 9,000 ft when carrying a heavy pack (overexertion?) or when taking the Palm Springs Aerial Tram (fast ascent). 2 summits of Mt. Whitney as dayhikes, once with no acclimation period.
* I'm not sure what the headache that comes with AMS feels like for others, but for me it feels like I've been hit in the back of the head at the base of my skull.
What happened (IIRC)
Hiker A - started struggling early on, first showing problems (headache, generally not feeling well) as we started the climb up to Cottonwood Pass. Since Hiker A had not been able to exercise recently and hadn't suffered from AMS previously, we figured that it was due to overexertion and not being in shape. By the time we reached Chicken Spring Lake, Hiker A was exhausted and had a horrible headache, took a nap and later vomited. We let Hiker A sleep for about an hour and made plans to get Hiker A off of the mountain. When awakened, Hiker A was doing much better, was able to eat and drink and was sharp mentally (the headache was gone), so as a group (group included a physician's assistant) we decided it was ok to stay on the mountain. Hiker A decided to not attempt Cirque the next day, but to sleep in. Hiker A had trouble sleeping through the night and the headache was back the next morning. On the hike out was exhausted.
Hiker B - hiked to Chicken Spring Lake without issue, but did not sleep well. Did not attempt Cirque Peak due to the cold temperatures. Suffered from headache on day 2 during the hike out.
Hiker C - hiked to Chicken Spring Lake without issue. Had trouble sleeping and had a headache most of day 2. Reached Cirque Peak, but had a hard time doing so. Descent was also very exhausting, suffered from nausea after trying to eat on Day 2.
Hiker D (me) - I started getting a headache and stiff neck around 10k feet. Headache went away after taking some ibuprofen at Chicken Spring Lake. Slept from 9pm - 12am, but between 12 am and 3:15 am woke up in a panic at least three times, feeling as though I could not breath. Reached Cirque Peak the morning of day 2, but was extremely exhausted and thought about turning around as I neared 12k feet. I was exhausted even on the ascent, when I realized I had not eaten since 7 pm the night before. Felt nauseous as soon as I started eating.
Possible Causes?
Hiker A - ate with my family and stayed at my house Friday night. On the drive to Lone Pine, we learned that my son had thrown up during the night and again Saturday morning. Since Hiker A had never suffered from AMS, we thought that the cause might be the same 'bug' that caused my son to be sick. Since he was mentally sharp after his nap and no history of AMS, we decided to stay on the mountain.
If AMS was the cause of the nausea, I wonder if part of the problem was overexertion. We all had heavy packs and Hiker A was reluctant to go on the trip because he felt he was 'out of shape.' My house is also at 1000 ft. I wonder is going from 1000 ft to 11000 in just a few hours was a factor. On Hiker A's Whitney hike, he had nights at the portal and Outpost camp before going above 11k feet.
Hiker B - I wonder if the symptoms were due to spending the night at such a high elevation. Hiker B wondered if the headache may have been due to a lack of caffeine.
Hiker C - performed well (IMO) based on previous hikes. Did great on the hike to Chicken Spring Lake, but I wonder if the lack of sleep and elevation finally took it's toll on day 2. Cirque Peak is a PR for elevation.
Hiker D (me) - I was surprised at how early and how much I struggled on the hike. In the end, it ended up being one of my toughest hikes ever, ranking up there with Cactus 2 Clouds and Mt. Whitney. The cross country route really took it out of me. To put this in perspective, I carried two packs for a portion my last training hike (March 29, total pack weight ~50 lbs for 3300 ft elevation change over 5.7 miles) and had a much easier time. This of course was at a much lower elevation (<6000). I was if my problems started early due to my (overly) heavy pack weight and not being able to exercise for the last 6 weeks (overexertion). I've noticed that when my pack is heavy (40+ lbs) I always get a headache that feels like I am suffering from AMS. On day 2, I feel that my physical exhaustion was partially due to not eating well and lack of sleep. From 11 am Saturday until 2 pm Sunday, I ate <3000 calories. My BMR is around 1900. I am wondering if trying to sleep at 11k was a bad idea, especially since I have been suffering from bad allergies (apparently) for the last 6 weeks. Maybe an intermediate step is needed before I sleep at this elevation.
Some Questions
1. If I am carrying a heavy pack (40+ lbs), it seems that I always suffer from a headache that feels like AMS. I've had this happen to be at elevations <10000 ft when carrying my son in a child carrier. Is it possible that the pack is resting on something and is causing this? Is it more likely that the headache is due to overexertion?
2. If someone vomits while hiking at elevation, do you automatically assume that it is AMS? Would you immediately descend? My gut feeling is that it should be assumed to be AMS until proven otherwise. As a side not, Hiker A is still dealing with stomach issues today (Tues). Sunday night, my wife (who was not on the trip) starting having stomach problems and still has them now.
3. I would like to hear any thoughts you have on our situation or similar experiences. I am open to constructive criticism.
