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El Capitan in heat wave on New Dawn Wall with Mountain Madness owner Mark Gunlogson

The heat is on! Neither climbers nor the mountains are immune to heat waves, as company owner Mark Gunlogson found out years ago during an ascent of El Capitan’s Dawn Wall.

What hap­pens when you climb a big wall in hot weath­er? Read about some lessons learned and how to man­age heat with your moun­tain adven­tures in a res­cue sto­ry in the Amer­i­can Alpine Club’s annu­al Acci­dents in North America.

It’s not just cold and wind that can knock you out of reach­ing goals to climb a moun­tain, climb a rock, or even go for a round of golf. As the sum­mer cranks up the heat for your activ­i­ties take some notes from the below sto­ry before head­ing out, and as we all know, stay hydrat­ed — avoid the suf­fer, cre­ate a buffer!



Cal­i­for­nia, Yosemite Val­ley, El Capitan

On Sep­tem­ber 22, 2004 Mark Gun­log­son (41) and I, Micha Miller (41), start­ed up New Dawn wall (VI 5.8 A3) on El Cap­tain. The weath­er before our ascent had been unsea­son­ably warm (low 90’s), with cool­er tem­per­a­tures fore­cast for the com­ing week. We con­sid­ered wait­ing for the bet­ter con­di­tions but were on a tight sched­ule and want­ed to get start­ed on the route. We planned on tak­ing sev­en days. Know­ing how crit­i­cal water would be, we each had three quarts read­i­ly avail­able for the first day, and five addi­tion­al gal­lons per per­son, packed away in our two haul bags, for the next six days (3.3 quarts per per­son per day). In addi­tion to what we fig­ured was an ample sup­ply of water, we were also pre­pared for fall storms, had a bolt kit, and, in short, were ready for any con­tin­gency — or so we thought.

Our goal for the 22nd was to climb three pitch­es and sleep at our high point, but it was very hot, and we moved more slow­ly than planned. We man­aged to fin­ish our three pitch­es, but we left the haul bags at the top of pitch two and returned to the ground for more water. We slept at Cur­ry Vil­lage, where we drank gen­er­ous amounts of fruit juice and Gatorade to replen­ish what we had lost.

High on the Dawn Wall route on El Cap.
Con­cave over­hang­ing face makes for per­fect place for heat to collect

On the 23rd we left the ground with three more quarts each, giv­ing us 3.8 quarts per per­son per day for the antic­i­pat­ed six days com­mit­ted to the wall. It was slow going, with heavy bags and dou­ble hauls — the fol­low­er would have to wait until the first bag had been hauled, before he could release the sec­ond bag and start clean­ing. Evening found us on Lay Lady Ledge (top of pitch sev­en, Super­topo”) after anoth­er hot day. We were tired and dehy­drat­ed, and we had drunk a bit more than our 3.8‑quart ration.

On the 24th we climbed to Texas Flake (top of pitch 11). The tem­per­a­ture remained high, with not even the slight­est hint of a breeze. Today, only our sec­ond con­tin­u­ous day on the wall, Mark’s mouth became so parched — prob­a­bly from breath­ing hard in the hot, dry air — that he gagged fre­quent­ly, trig­ger­ing dry heaves. He suf­fered this for the next four days.

On the 25th we com­plet­ed the tra­verse to the top of pitch 13 of the Wall of Ear­ly Morn­ing Light (pitch 14 of New Dawn). For more effi­cient haul­ing we had con­sol­i­dat­ed all of our stuff into one haul bag, but we could do noth­ing about the weath­er, which con­tin­ued unchanged. This was Mark’s tenth ascent of El Cap and my sev­enth, and nei­ther of us had seen such a long peri­od of both high tem­per­a­tures and breeze­less con­di­tions on the wall. We had pressed on because we knew” from expe­ri­ence that, at the very least, dai­ly ther­mal winds would kick in, and that tem­per­a­tures would drop as we got high­er. How­ev­er, this was prov­ing not to be the case, and by this point we were thirsty all of the time. It was time to ration our water. We ate very lit­tle at meal times because we had brought dry food (not as much moist canned food as usu­al), and our thirst inhib­it­ed our hunger.

On the 26th (our fourth con­tin­u­ous day on the wall) we climbed three more pitch­es to Wino Tow­er and fixed one pitch. At Wino Tow­er (com­plete with bro­ken wine bot­tle) we reviewed our progress and the water remain­ing. Our thirst con­tin­ued to increase and we had invol­un­tar­i­ly reduced our food intake even more. Our allow­able water ration at this point was inad­e­quate for our needs, even though we were still drink­ing about 3.5 quarts a day per per­son. If we man­aged to sub­sist on this ration, and climbed at this pace, we would need a half day more on the route than we’d planned and be just out of water as we fin­ished. But it didn’t work out that way.

Midway up Dawn Wall
Still smil­ing before we with­er up from dehydration

On the 27th we pushed hard and reached the top of pitch 22, a hang­ing belay under a large roof. I was so dry now that my sali­vary glands had shut down, and I couldn’t swal­low with­out first adding water to my mouth. It took me an hour to eat a Clif Bar. Mark’s dry heaves con­tin­ued and his tongue got so phys­i­cal­ly stuck in his mouth that he had to push it around with his fin­ger. We were feel­ing very weak and a lit­tle pan­icky, as con­di­tions remained hot and wind­less. Even the nights had been hot; we slept with our sleep­ing bags bare­ly cov­er­ing our­selves. Mark went the day of the 27th with­out uri­nat­ing, and I only uri­nat­ed a small amount in the evening and ear­ly morn­ing, none dur­ing the day.

High on Dawn Wall on El Cap
There’s the dysen­tery diet you get on expe­di­tions and the dehy­dra­tion diet on big walls, both deplete you off your bod­ies water and make you look good on the scale, but feel real­ly bad otherwise.

The 28th was our sixth con­tin­u­ous day on the wall, and was to have been our sum­mit day. We called a friend with our cell phone and asked him to meet us on top with water. We climbed pitch 23, the Dawn Roof, and stopped, com­plete­ly exhaust­ed, with four pitch­es to go and one quart per per­son left. The sun was relent­less and the heat radi­at­ing off the rock felt like a sauna. We had found a lit­tle shady cor­ner and I was think­ing, Should we go until we col­lapse?” Then I put my arm out in the sun and that did it! It was scorch­ing. I thought, I can’t go out and lead this pitch.”

We called the NPS res­cue team at about noon and told them our sit­u­a­tion. Water was all we need­ed and we didn’t want to be hauled up. The rangers told us they would fly a team to the sum­mit, low­er a medic to us with sev­er­al gal­lons of water, and make the deci­sion then. We drank our last quart, and waited.

Our sav­ior arrived about three hours lat­er. He checked us over, decid­ed we could con­tin­ue, and left us on the route with four gal­lons, plus more that he would leave on top. We slept 12 hours that night after drink­ing our fill and final­ly eat­ing a large meal. The next day was a dif­fer­ent world. We were tired, with aches that mys­te­ri­ous­ly appeared for the first time as we re-hydrat­ed, but the cot­ton-mouth was gone and we felt stronger. We topped out that evening hav­ing drunk about two gal­lons each in the pre­ced­ing 24-hour period.


Did we ask for a res­cue because we had a cell phone and help was near? Maybe. But in our con­di­tion, either of us could have made a fatal mis­take while climb­ing, or suf­fered heat stroke, with the same result. I’d been dry before and I thought I knew what dehy­dra­tion was all about. We nev­er doubt­ed that we would be suc­cess­ful. It just had to get cool­er, or maybe we would find water on a ledge high­er up. But we were wrong, and we lost — we were tru­ly cooked.

What to do as climbers? Accept that we run a razor’s edge on dehy­dra­tion. We rarely take enough water for our needs on big walls. Every big wall climber can attest to dark urine, infre­quent uri­na­tion, and thirst. That is the real­i­ty of climb­ing in the sun­ny world of Yosemite, but you still can’t defeat the phys­i­ol­o­gy, so take at least a con­ser­v­a­tive min­i­mum. The aver­age per­son los­es about 2.5 quarts per day just sit­ting around, and the aver­age ath­lete los­es about one quart per hour dur­ing mod­er­ate exer­cise. So it’s not sur­pris­ing that we prob­a­bly need­ed about five quarts per per­son per day to do the climb — dehy­drat­ed but func­tion­ing — in the con­di­tions we expe­ri­enced. That totals 15 gal­lons (125 pounds) for the two of us, in the haul bag.

What else would we do dif­fer­ent­ly next time? Do not base plans on a weath­er fore­cast — plan for the worst, hope for the best. Bring an emer­gency stash beyond the care­ful­ly cal­cu­lat­ed rations, to com­pen­sate for dropped water, unfore­seen delays, and unex­pect­ed weath­er. Sub­sti­tute moist canned food, e.g., canned fruit, for some of the water, to keep caloric intake high. Min­i­mize over­ly sweet water (Gatorade, etc.) or dilute it to avoid sticky mouth.” Keep the day’s rations eas­i­ly avail­able and remind each oth­er to drink. Start ear­ly each day and/​or climb at night if con­di­tions war­rant, to reduce water loss. Bring a cheater stick to assist dif­fi­cult retreats. We did not and decid­ed it would be eas­i­er to con­tin­ue up than to attempt a risky descent. (Source: Micha Miller and Mark Gunlogson)

(Editor’s Note: It is always appre­ci­at­ed when those direct­ly involved in an inci­dent write such thor­ough reports. Oh, and for those of you who are not famil­iar with a cheater stick, ” here’s the word from John Dill: It’s a short pole — 3 – 4 feet long — with a cara­bin­er (or oth­er gad­get) attached at the far end. You use it to clip pro­tec­tion that is out of your reach. If you re lead­ing a hard aid pitch, you can cheat” by reach­ing past a dif­fi­cult place­ment. On an over­hang­ing rap­pel, you can reach in to the wall, clip a bolt hang­er or oth­er fixed pro, and there­by stay close to the rock. Sticks used to be home-made (tent poles, etc.) but there is at least one com­mer­cial mod­el now.)