Humphreys Peak
Arizona
June 2013
Y’know what’s great on the trail? Potato chips. Like that magical food bacon, potato chips always taste good. The salt doesn’t hurt either on a day as strenuous as this one. We’re at 11 800 feet, on our way up, and it’s potato chip time! I take the package out of my pack and find that the hermetically sealed bag is swollen, puffed up like a pillow. It looks like it’s going to explode. In fact, just as I say to Lisa, “It looks like it’s going to explode,” she tears a small corner of the bag, and… It explodes! Potato chip chips everywhere.
We’ve climbed up three miles from trailhead and take our rest at the Saddle, a low point between two prominences. This is a popular resting spot for hikers to refresh and enjoy the glorious panoramic views. Coming up next is the 800-foot climb up to the summit of Humphreys Peak at 12 633 feet.
In non-highpointing life, we live below 1300 feet. Lucky us, today’s high altitude is not much of a challenge for us. Perhaps we take an extra breath every so often, but the thin air is comfortable. This was true on the first three miles of ascent, up from 9260 feet to the Saddle, and we hope it remains true for the rest of the rocky, even steeper trail to the top.
High altitude. Experts say that when you ascend to 8200 feet or more, you have entered the high altitude zone. When at this level of the troposphere, one must be aware of a phenomenon called HAPE. There are two types of HAPE.
One type of HAPE is “High Altitude Pulmonary Edema.” This condition can be as scary as it sounds. High Altitude Pulmonary Edema is an ailment where fluid accumulates in your lungs. Gas is what’s supposed to be in there, y’know, oxygen and carbon dioxide and such. When fluid gets into the lungs, it inhibits oxygen uptake and interferes with the release of carbon dioxide. This impairs lung function with nasty consequences.
Let’s say you are hiking in the high altitude zone. When we rest in the Saddle at 11 800 feet, we are at about 2/3 normal atmospheric pressure. The percentage of oxygen in the air is the same as sea level, about 21%. The problem is that there just isn’t as much air as we’re used to down at the beach. In terms of volume, this means there is less oxygen. It’s not the lack of air to breath, it’s that there is less air and therefore, less oxygen. It’s the lack of O2 that causes the symptoms of Acute Mountain Sickness or worse, High Altitude Pulmonary Edema.
My friend and hiking partner Mike, wilderness responder, trainer and mountain climber, explains High Altitude Pulmonary Edema…
“It can start with shortness of breath at rest, a wet gurgly productive cough with lung sounds and pink sputum. It can advance to tachycardia (an abnormally rapid heart rate,) seizures, coma, respiratory arrest and death.”
Doth tend to hinder the progress of your hike.
Pay attention. If the labored breathing and gurgling and wheezing don’t get your notice, take a clue from the pink sputum. You really don’t want pink sputum on your hike. It’s just plain icky.
As you know, sputum, which is coughed up phlegm, is divided into five categories, depending on color. In addition to pink phlegm, which we’ve already met, there is white, green, brown and dark yellow too. The pink is a sign of Pulmonary Edema, or fluid in the lungs. This is bad. Mike amplifies by saying that it is potentially deadly. Try not to make phlegm in your lungs.
As an aside, I submit that there is not a more onomatopoeic word in the language than phlegm. It sounds exactly like what it is.
Okay. So you’re climbing up over 8200 feet. HAPE is a possibility. More likely though, before HAPE begins, you will experience what we call “Acute Mountain Sickness.”
Take it away, Mike: “The acute part refers to its rapid onset, not to its severity. Acute Mountain Sickness means you may get a headache, you could get lightheaded, you may experience nausea, insomnia, loss of appetite and shortness of breath when exercising. AMS is not a life threat, as long as it resolves itself within 24 hours.” Mike’s training prescribes that if you have these symptoms, “…eat and drink well, do some light exercise, take an aspirin and/or Vitamin I.” (Vitamin I = ibuprofen.) If the symptoms aren’t gone in a day, get the heck down from the mountain, toot sweet. Once down, the condition will most likely resolve.
All this is in the back of my mind as we prepare to ascend from the Saddle. I have never been higher than eleven thousand feet before and this hike adds 1600 feet of unknown.
Okay, I admit, my breathing is labored, but only a little. I must stop to catch my breath once or twice, more than in the lowlands of the eastern United States. In fact, at one point I am thinking, “So this is what it must feel like to be 60.”
I’m told that one in three hikers turns back on this hike, usually because they have trouble catching their breath, or the headache comes, or they feel kind of hinky, ill at ease.
Earlier, I mentioned that there are two types of HAPE. We’ve just reviewed High Altitude Pulmonary Edema. Very serious. Don’t get it.
The second type of HAPE is High Altitude Pressure Equalization. While this doesn’t sound as scary as Pulmonary Edema, it can cause your fellow hikers to run for their lives.
As you ascend, the atmospheric pressure diminishes. At sea level, we have a pressure of one atmosphere, or 29.92 inHg, or just under 30 inches of mercury. In geek talk, this is the amount of pressure exerted by a one inch diameter circular column of mercury one inch high at 32°F at the standard acceleration of gravity. Even if this does not sound familiar, you’ve heard of it. It’s what the weather announcer refers to as “barometric pressure.”
My friend Steve explains that saying “…one inch diameter circular…” is redundant. I told him it would take me a while to completely understand this. He said, “Take your time. No pressure. Pun intended.”
So as I say, as you move up higher, the atmospheric pressure goes down. When we get to the top of Arizona, Humphreys Peak, we are just shy of standing two and a half miles above sea level and the pressure has dropped to 0.64 atmospheres, or just a gnat’s ass under 2/3 the amount of air pressure with which we are familiar.
Here’s the point. When the pressure of the atmosphere drops, the pressure inside your body remains constant, but relative to the outside air pressure, it increases. Greater pressure inside tries to do to you what the altitude does to our potato chip bag.
The relative pressure inside the potato chip bag is about one and a half times normal. We learn, and rejoice, that high pressure potato chips are just as satisfying.
We are like walking potato chip bags: full of gas, lots of internal pressure. Don’t worry, it’s normal. Even at altitude you won’t inflate like the potato chip bag because physiologically, your body has a way to equalize the pressure, an escape valve, so to speak, and you don’t even have to try to do anything in particular. In fact, you just relax.
And then you fart.
Usually more than once. Usually a lot. This is High Altitude Pressure Equalization. It just is. And you’re not the only one up here who is HAPEing. So toot away!
It’s better to fart and feel the shame
Than hold it in and feel the pain.
Just one more thing, as long as we’ve slipped sideways into juvenile merriment. FART too, is an acronym. It stands for Fire Assisted Rear Transport. I would say that a little jet propulsion might be just the thing to help you climb up these steep mountains.
Grateful thanks to my friends Mike and Steve for their contributions, corrections and explanations regarding this column.
