Aconcagua Pre-Trip Information


FACT: The dry air desiccates both you and the snowfields.


Our friend, mentor, hero, company physician, and director of the Institute For High Altitude Medicine Dr. Peter Hackett has published the following list on the Institute’s very informative website:

Myth # 1 – Don’t drink caffeine at altitude.

We don’t know where this false assumption came from, but likely from the fact that caffeine is a mild diuretic (makes you pee). The concern is that it could dehydrate you and contribute to altitude sickness. This concern is unfounded unless you drink copious amounts of black sludge coffee each day and little else. In reality, caffeine stimulates your brain, kidneys and breathing, all of which are helpful at altitude. And for those people who drink several caffeinated beverages a day, stopping abruptly can cause a profound headache and affect performance. (Tell Mountain Trip ahead of time if you are a coffee drinker!)

Myth #2 – Diamox masks symptoms of altitude sickness.

Taking Diamox to prevent AMS will not mask symptoms. It works on the same pathway that your own body uses to help you acclimatize. It is a carbonic anhydrase inhibitor which makes you urinate a base chemical called bicarbonate. This makes your blood more acidic and therefore stimulates breathing thereby taking in more oxygen. It speeds up your natural process of acclimatization and if you stop taking it you will not have rebound symptoms. It is one of the main medicines doctors use to prevent and treat acute mountain sickness (AMS).

Myth #3 – Physical fitness protects against altitude sickness.

Physical fitness offers no protection from altitude illness. In fact, many young fit athletes drive themselves too hard at altitude prior to acclimatizing thinking they can push through the discomfort. They ignore signs of altitude illness thinking it can’t affect them because they are fit and healthy. Everyone, regardless of fitness, is susceptible to AMS.

Myth #4 – Drinking extra water will protect you from altitude illness.

Staying hydrated is important at altitude. Symptoms of dehydration are similar to AMS. In reality you only need an additional liter to a liter and a half of water at altitude. Too much water can even be harmful and can dilute your body’s sodium levels (hyponatremia) causing weakness, confusion, seizures, and coma. A good rule of thumb to assess for hydration is to check your urine. Clear urine indicates adequate hydration, dark urine suggest dehydration and the need to drink more water.


Mules are our friends.  “Las mulas son nuestros amigos!” 

Aconcagua Mules and Arriero

Don Fernando Grajales, father of our mule and Base Camp logistics provider, Fernandito, developed the system by which everyone now climbs Aconcagua, using mules to bring in food and equipment to the base of the mountain.  Fernandito has worked hard to instill a very high level of quality and service in the work ethics of his “arrieros” (local term for mule drivers- please do not use the derogatory “muletero” that you might hear others employ).  They are themselves hard workers and are very good at their profession, although they might be barely literate in some cases.

We treat them with the same respect and show them the same gratitude that we would anyone who helps us provide you with the very best experience.  In return, they take exceptional care of our equipment and provide us with benefits like shuttling us across the frigid Rio Vacas on horseback, while other climbers are wading across in their skivvies (brrrrrrrr…).  Please treat them respectfully, and they will embrace you with the warm traditions of the gaucho.  They will cook for us on the hike in, and might offer you a sip of “yerba” from their “mate,” a very social custom of passing around a hollowed out gourd filled with tea, which is sipped through a metal straw (bombilla).  It’s fine to politely refuse, but indulging in the experience can add a cultural dimension to your experience.

What to wear?  Thoughts from Todd: 

I like to bring a set of clothes for the hike in that I then send back out from Base Camp.  This strategy allows me to head up the mountain with fresh, clean clothes that are not dusty from the dry, windy Vacas Valley.

I prefer to wear a short sleeved sun shirt made of nylon that is vented.  Buttoned shirts allow me to “dial in” my ventilation, and if my neck feels like it’s burning, I can tip up the collar, achieving an Elvis look and a practical additional level of sun protection.  Nylon shorts with pockets allow me to keep my lip balm and sunscreen close to hand.  I also keep either a bandanna or a light weight, Buff designed for sun protection in the top of my pack, because it can get really scorching down there.  A wide brimmed hat completes my daily trekking ensemble, but many folks are happy with baseball hats.  Go with what suits you, but please keep sun protection at the forefront of your mind each and every day.  To that end– keep applying liberal amounts of sunscreen to your hands, as the webbing between your thumb and forefinger will get baked while holding trekking poles.

I keep a rain jacket in my pack and a light insulating layer, just in case.  You’ll need plenty of sunscreen, which I recommend bringing in the form of several small tubes, rather than one big bottle. The sun also dries you out, so you’ll want to have two 1L water bottles or a hydration system (CamelBak), which I prefer.  The latter is nice as I feel more inclined to sip from a tube while reclined in my tent than make the effort to sit up and unscrew a water bottle, resulting in a higher overall level of hydration.  If you bring one– insulate the tube!


After reaching Base Camp, consider sending your trekking clothes out with the mules, so that you can begin your climb with fresh clothes.  This is a bit risky, as there is a chance that things being sent out to Penitentes can get lost or misplaced, but the better we treat our arrieros, the more care they will provide to see that our kit makes it back to us.  I even send my rain coat out and just bring a light wind shell for the upper mountain.  This is also a bit risky, as it could rain on the hike out from Plaza De Mulas, but I’m OK taking that risk on a personal level.  I have my puffy and wind shirt, which will keep me mostly dry, if need be.

Have we effectively communicated this? 

Climbing big, cold mountains is risky business.  Employing a guide to help orchestrate a safe, successful outcome is a great way to help mitigate some of that risk, but you need to take responsibility as well.  The best way you can help insure that you come home with all your fingers, toes, and with memories from a place with amazing views is to communicate with your team mates. Our guides have extensive experience with problem solving in the mountains, but they can only solve those problems that they know about.  They will constantly ask you how you are feeling and remind you to eat, drink and apply sun protection, but you need to take an active part in your own experience as well.  Be proactive.  Drink, eat and apply sunscreen and lip balm at each rest stop.  Strike up a dialogue amongst team members about how everyone is feeling and be honest in your own self-evaluations.

If you’re feeling a bit off, let one of the guides know.  You’re heading way up high on a big, chilly mountain and everyone will have days when they feel off.  Off is OK.  You might find yourself with a headache or other symptoms of Acute Mountain Sickness (AMS).  We often tell our climbers that it is OK to have AMS, but it is most certainly NOT OK to die from it.  Communication is a key factor between the two.

Everything the guides tell you is designed to improve your experience with us.  They are some of the most patient, able and capable people I’ve ever had the pleasure to call friends, and they will go above and beyond your expectations if you are honest and straight with them.  Please communicate regularly and candidly.

The reason I’m driving this home so hard is that we’ve had a couple of incidents where climbers withheld information from us, and as a result, we’ve had some scary times.  One woman didn’t reveal that she was taking Amoxicillin, and we thought her symptoms were that of an intra-cranial bleed from HACE, rather than her allergy to Penicillin.  Yup- scary stuff happens in the silences.

We’re all on the same team and we can achieve great things if we work together, so I’ll say it again:  communicate, communicate, communicate.

What to wear?
Conditions on the mountain can vary drastically from day to day and from trip to trip.  It is not uncommon to not touch fresh snow during your ascent, but we’ve also broken trail through waist-deep powder.  The clothing you’ll need for any given day will therefore also vary accordingly. In general, you will often travel in fairly light layers, maybe even shorts.  We are “big picture realists” and won’t “make” you wear your big burly boots if the terrain and conditions are such that your trail runners will suffice.  We’ve had trips where we didn’t put our mountain boots on until summit day, and others where we wore them in the valley on the approach, so be prepared to remain rigidly flexible during the course of the expedition.

Porters and “luxuries”
We are providing porter support so that we can keep your loads to a minimum, but please do not take this as a license that you should bring 20 pounds of additional, potentially unnecessary gear without abandon.  We will have a satellite phone that you are welcome to use occasionally to call home.  If you know that you’ll need to make calls, please let us know ahead of time or bring your own phone or SIM card for the Iridium network, as our phone is primarily for emergency use and for calling in the daily dispatches and podcasts for updating your expedition blog.  Before you leave for the expedition we will email the blog address and also the link to it from the Trip Reports Page of our website (more on that in later emails).

We are fans of flash drive MP3 players such as the iPod Nano.  Hard drives will fail up high, so don’t bother bringing your iPad or even larger iPods.  We’ll have a solar charging system that you are welcome to use, however you need to keep in mind that the primary reason for the system is to keep our radios and sat phone charged, so those have priority.  Good options for personal chargers are from Solio and Powermonkey.  Both make versions with built-in lithium ion batteries that allow you to charge during the day and dump power to your gadget in the evening.

Bring a book or two for the mountain, as they provide good trading material when you finish them.  E-Readers such as the Kindle are compact and seem to work well, but we’ve had mixed results with them on expeditions, so we’re holding off on recommending them.

We will follow a climb high-sleep low philosophy during our ascent.  This allows us to effectively ease our bodies into new elevations and enables us to better acclimatize.  We also have plenty of contingency days built into our schedule, so if you are feeling off and communicate it effectively (hate to beat that horse any further, but I can’t help myself), it is generally easy to take an extra day at a given camp.

The distance between our camps is quite moderate, and we will climb slowly and methodically.  Some might find the pace a bit stifling, but keeping our bodies working in an aerobic state will allow us to better utilize our fuel (food and fat- what did you eat over the holidays?).  If we need to split up into faster and slower groups, we have that option, but it is best to just take our time and enjoy the views.  If you find yourself walking quickly for a few minutes and then taking a short breather, you’re working inefficiently.  Strive for a pace that allows you to keep moving for 45 minutes to an hour.

Acon Bombshelter at C2

We often use Bibler Bombshelter tents on our Aconcagua expeditions.  These are the best tents on the market for this sort of climb, but you’ll not see many on the mountain, because they are very expensive.  They are single walled tents and are very quiet in the high winds Aconcagua is famous for.  They are very easy to set up, but do require a bit of care at certain steps of the set-up process.  Please take care with these tents, and let the guides know if one gets damaged, so we can repair it in short order. Bombshelters are marketed as a four person tent and comfortably sleep three.  We’re a bit indulgent and generally only sleep two to a tent, so enjoy the space.  Tent partners are up to you all, but if you have a preference one way or another, feel comfortable to take a guide aside and request that you not sleep next to Joe, who snores like one of the mules.


Climbing big mountain is certainly serious business, but we can go about that business in many different manners.  We prefer to have as enjoyable an experience as possible, which means that unless a situation presents itself that calls for seriousness- let’s all have as much fun as possible.


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