Mount Everest is Way More Dangerous Than You'd Think.

Just before we get started, have you seen our fantastic merch store? Well, if you haven't, there's a link below, and if you have, I don't know, just go buy something. Sorry, I'm supposed to have some copy in here to read to you about an ad for the places store, but it just says, Simon, do an ad for the places store. So that's what I'm doing. We've got all sorts of cool stuff. I'm in a temporary new studio right now. I don't have my normal poster up here on the left because it's being renovated. They're putting some sound panelling in, so the audio sounds nicer. You're welcome, everybody. And why not help me pay for it by buying one of those posters? There's a link below. Everest isn't just the world's tallest mountain. It's really quite dangerous. From air that is too thin to breathe, to cold that can put you in a tangle in mere moments, to geographic features that can claim your life whenever they please with no warning or quarter offered. Well, Everest's got the lot, hasn't it? And even then, that's before you factor in the human element. Crowds and their consequential bottlenecks, and even just poor decision making. They are, both of them, every bit as deadly as that which the mountain itself puts before you. A bucket-less destination, Everest may be. The climb to eclipse all others. But a bracing merch up Machu Picchu, or a hardy romp up to the top of Mount Fuji, this is not. Which is exactly why a not insignificant percentage of those who try to conquer Everest never come back down. Let's find out why. The most apparent danger of Everest is the sheer height of the summit standing at 8,849m above sea level. For reference, an airliner typically cruises at somewhere in the region of 9,000-13,000m. So yeah, it's f***ing tall as s***. It's a shocking thing to say about the world's tallest mountain, we know. And look, us humans, we're not designed to exist at such heights. They're downright lethal to us, in fact. Hence why the altitude vaguely above 8,000m is known as the death zone, because when there's no two ways about it, your body is shutting off and it's going to die. Slowly but surely. Chiefly, this is due to the oxygen, or lack thereof, at such heights. By the way, complete side note here. Did you guys see that video? I think it was by Red Bull, of the guy skiing down Mount Everest. Like, he hikes the f*** up there and he skis down it. It was awesome. You see, air, including the oxygen that we need to stay alive, is a physical thing with mass, so it is affected by gravity, which pulls it down toward the surface. But it doesn't just get pulled down into a thick blanket at ground or sea level, because air molecules are always smashing into each other and therefore bouncing around at incredible speeds, and with this happening with genuinely countless frequency, it settles into a dependable pattern of density. Now, we could put some exact figures on this as well, thanks to the work of respiratory physiologist John West, who led an expedition up Everest in 1981 and then did all manner of interesting experiments while he was up there. And from those experiments, we know that the pressure up on the summit of Everest hovers somewhere around the 250-253 torr sort of mark, specifically when the mountain is usually climbed during May and October. Now, if you were wondering what a torr is, yes, we also had to look it up. It's just a pressure unit, and if you translate it into a unit that normal human beings actually use, you end up with roughly 335 hectopascals, as compared to about 1000 hectopascals at sea level. In other words, up at the top of Everest, the barometric pressure is only about a third of what it is down at a beach, so the pressure of oxygen in each breath is drastically lower. That also means that all the death zone actually is is the altitude where acclimatization basically becomes impossible and the body starts losing ground even if you stop moving. And what does that actually feel like to experience? You probably want to know. Well, according to the American mountaineer and filmmaker David Brashears, who climbed Everest five times during his life, climbing above 8,000 meters, even with bottled oxygen, is like running on a treadmill and breathing through a straw. That's very much a headline or TLDR summary of the matter, though, because the lack of oxygen up on Everest also causes some far more specific physiological effects than just your lungs proving utterly insatiable in the appetite for oxygen, no matter how hard you breathe. For example, one Dr. Peter Hackett, speaking to PBS back in 1998, stated that, quote, judgment becomes impaired, a person becomes confused, they don't even know where they are as it gets worse, people hallucinate. So all sorts of mental changes can take place as the brain starts to become more and more abnormal. And it isn't just oxygen deprivation, per se, that causes such phenomenon, either. It's something called high-altitude cerebral edema, or HACE, a consequential follow-on from oxygen deprivation where your brain literally starts to swell up inside your skull. Which isn't good for your brain, is it? Basically, how it works is the arteries feeding your brain panic, and open right up to try and ram more blood and thus pressure oxygen through. That extra flow, plus the chemical chaos that comes with severe hypoxia, makes the microscopic blood vessels in your brain wall go leaky. Fluid then starts to seep out of them, into the brain tissue, like water into a sponge. And at the same time, the brain cells themselves are so short on oxygen that their internal pumps, the little molecular machines that normally keep salt and water in balance, begin to fail, so they start puffing up, too. Then, because all of that swelling is happening inside a rather inflexible bone helmet that has no flex or given it, the pressure in your skull rises. The delicate wiring of your brain then gets thrown out of whack, and your thoughts, balance, personality, and grip on reality begin to unravel. We have some solid numbers to consider alongside all of that, too, because in 2007, British doctor Jeremy Windsor, climbing Everest as part of the Caldwell Extreme Everest Research Expedition, drew some arterial blood from four climbers while perched on The Balcony, a tiny little ledge some 8,400 meters up. And he summed up the whole experiment and his findings therefrom as follows, quoting, A very simple question was answered. What happens to our oxygen levels at 8,000 meters? The answer was incredible. Blood samples were taken, these were stored in ice, and rushed down the mountain where they were processed. The results revealed that the mountaineers were surviving on just one quarter of the oxygen they needed at sea level. These were comparable to figures found in patients on the verge of death. Extraordinary. End quote. And what can we say about that, other than… quarter? We aren't exactly what you'd call medical professionals here or places, but that certainly helps it fall into place in our minds. However, let's not simply reduce all of this to a mere matter of intellectual curiosity. Because yes, while it is certainly interesting to learn about exactly how the extreme conditions up on Everest affect the human body, as it is also interesting to hear the testimony of people who did experience it and survive, there is no shortage of people who experienced it and didn't survive. People like, say, Scott Fisher, who went up in 1996, made it to the summit well enough, but then deteriorated quickly on his descent, before ultimately collapsing and passing away at 8,300 meters. According to his Sherpa, Lobsang Jangbu, haste was always no small part of what tragically got him in the end. Consider, also, Francise Arsentiev. She made the ascent in 1998, being the first American woman to ever do so without supplementary oxygen, but she died high on the mountain during the descent. And it's worth circling back to how she did it without supplementary oxygen, because yes, the vast majority of people who climb Everest do it with big old tanks of oxygen on their backs, but right on the sharp, purist edge of things, there does indeed exist a minority who totally forgo it, with it being Reinhard Messner and Peter Haberle who first proved it was possible on their 1978 ascent. All their doing that did, however, was to evolve the question of can you climb Everest without bottled oxygen to should you climb Everest without bottled oxygen. It's a surprisingly contested matter, you see. Some — most, in fact, as far as we can tell — remain ardent that to climb Everest without supplemental oxygen is a pretty silly idea. But then there's also a minority who are all about it. What's not up for debate, however, is the fact that it is more dangerous to some degree. As evidence for that claim, consider a 2000 study published by the University of Washington of 1,173 Everest summiters from 1978 to 1999. It found that 3% of climbers using supplemental oxygen died on the descent, compared with 8.3% who did not use it. Pretty clear numbers there. Either way, because we aren't going to pretend to be anything like a suitable arbiter in the matter, what we've learned in this section remains unchanged. Everest, simply through its height alone, will try to kill you. It's the unavoidable baseline of the mountain. While up there, above the 8,000m mark, you are operating on ungodly low levels of oxygen, your brain and body are slowly failing, and if you're unlucky or unsuitably prepared, that which is failing will fail, and you won't come back down again, just as hundreds of climbers before you didn't. And that's not the only danger, because as you can see from the runtime of this very episode, we've got more perils still to discuss. Perils like, say, the weather you get up there, which is… extreme, to put it mildly. Consider the temperatures alone. Because according to University of Toronto professors George Moore and John Semple, who wrote a whole paper about exactly this back in 2011, high up on Everest, they routinely plummet below minus 30 celsius, and that's just as a true temperature. Throw windchill into the equation, and suddenly we're talking more like minus 45 celsius. And what do temperatures that low do to you, you ask? Well, according to Moore and Semple, again because they talked about exactly this too, it isn't just that it's very cold, it's that it's so cold so often that you can literally timetable in how long catastrophic cold-related injuries take to come about, with them using what they call the facial frostbite time to do exactly that. It's a metric that's exactly what it sounds like, the average time that exposed skin on the face, the most likely part to be exposed at some point during an ascent, takes to physically reach the freezing point of human tissue and begin forming ice crystals, i.e. the onset of frostbite. And according to them, near Everest's summit, the typical frostbite time is always under 20 minutes, and in the spring climbing season, it's typically about 5 minutes, with severe storms pushing it down further still towards 1 minute. And it's not just about the skin damage either, the real killer is what the cold does to your body's ability to function more broadly. You see, your body prioritises its core for survival, and not without good reason. You can survive without an arm, or a leg, but lose any of those vital organs squished up in the middle of you and you're pretty cooked, or chilled. It really is your body choosing to sacrifice the bits that you can maybe survive without in the most literal sense. The blood gets pulled away from your extremities, your fingers, your toes, your arms, your legs, and it goes straight to keeping your brain and your heart warm. It's all very conscious on your subconscious' part. And of course, all of that comes at a price up on Everest, because as you lose blood flow from, say, your fingers, your dexterity goes, and suddenly you're fumbling with buckles that you could flick open with a finger down a base cap. And that oxygen valve that you opened easily before, you can now barely even get a grip on the thing. That in turn slows you down, which leaves you exposed for longer, which slows you down again, which leaves you exposed for longer again, and so on and so forth in what could quite easily become the quite cataclysmic cycle. Moore and Semple themselves discussed this particularly vicious loop, in fact, and provided a case study. Two different climbers, Lincoln Hall from Australia, and David Sharp from the UK, both of whom made the ascent at different times in 2006, but also both had to spend a night out near the summit after things went awry. For Hall, it was in late May, and after summiting from the north side, he fell badly ill on the descent and could not carry on. His Sherpa team eventually left him high on the mountain when their own oxygen was running out, reasoning that there was nothing further to be achieved by their staying other than making one corpse into three. However, in defiance of any reasonable expectation, the next day Hall was still alive. He just about managed to draw attention to himself as fresh summiters passed and was rescued, eventually making a full recovery. Sharp, however, did not survive his equivalent ordeal. He made his ascent a week or so before Hall, and after setting off late, climbing solo, carrying only two bottles of oxygen instead of the go-to five, and not bringing a radio — not far off everything you could do to tempt fate, basically — he was up on the north side, badly depleted and unable to go on. He took refuge at Green Boots' Cave that's 8,500 meters up, so-called, because it contains a particularly famous body wearing the titular footwear, typically believed to be T-Swan Pyor, who died on a 1996 ascent. By the time other teams encountered him the following day, he was still alive, but he was severely hypoxic and badly frostbitten, to the extent that even when people did try to rouse him and even share oxygen, he couldn't properly respond or get to his feet. In total, over 40 climbers would pass him before he himself passed. He was the same mountain, the same season, the same basic rough height, the same basic nightmare scenario. Alone, hypoxic, sitting out in the night in the death zone, but two completely different endings. And to figure the reason for the differing outcomes, Moore and Semple stripped away all of the drama and asked a really simple question. What was the weather actually doing? And their answer was grimly simple. Hall got lucky with the weather. Sharp didn't. Hall was in conditions that were ever so milder than the seasonal norm, while Sharp was in conditions that were ever so harsher than the norm. This was all on the order of just about a standard deviation either side. That was it. One tiny flick away from the norm either way, and two completely different outcomes. So extreme is the weather up on Everest that when things go wrong, fluctuations that small can make the difference between life and death. And that's just the cold bit of the weather. We haven't even begun to consider what happens when snow and wind get thrown into the equation as well. Perhaps an example would explain it best. Specifically, the 10th through the 11th May 1996 Mount Everest disaster. It started out straightforward enough, or as straightforward as anything ever is on Everest, with multiple commercial teams, including one led by Kiwi Rob Hall and American Scott Fisher, all starting out on the south route. But it didn't take long for things to start going wrong, with climbers finding that multiple fixed ropes had not been set to key technical points like the balcony and the hillary step. A queue then formed as groups that had set off well spaced from one another all stumbled into the same bottleneck that they could basically do bugger all about. And that took a long time. So long that come 2pm, the usual safety first, give it up, go back time, multiple groups were still heading up the mountain. Then, right at the worst possible moment came the turn in the weather. Snowfall and wind that just built and built through the afternoon and into the evening. The well trodden track was gone. The fixed ropes were gone. Visibility was gone. And because of it all, 33 climbers were trapped up on the mountain. By the time things cleared the following day, 8 of those 33 were to remain on Everest forever. Both Rob Hall and Scott Fisher, adventure consultants, guide Andy Harris, clients Doug Hansen and Yasuka Namba, and 3 members of an Indo-Tibetan border police team on the north side, Dore Marop, Tswang Smlana, and a name that should sound familiar, Tswang Payaw. And make no mistake, clear and evident mistakes were made on that tragic day. The ropes, the ignoring of turnaround times by some. But none of them, on their own, locked in the disaster. They only did their damage when the weather piled in on top. Once the wind and snow wiped the trail, buried the ropes, destroyed visibility, dropped temperatures and stranded 33 climbers up on the mountain. Now, up until now, we've been talking about Everest trying to kill you in a metaphorical kind of way. Because, while the weather and the temperature are part of the mountain in a sense, they aren't an actual physical part of the 8,849m lump of rock, are they? Icefalls and crevasses, though? Well, they absolutely are. They are the mountain's own built-in booby traps, in fact. Great walls of flowing ice and deep, dark holes that can swallow you in a second if you put even so much as a boot wrong. And for the former, there is no better example of that than the Khumbu Icefall. It's not even that high up by Everest's standards, either, sitting just above base camp at an altitude given as 5,486m on the southern side of the mountain. So not only are we not talking about the final push between Camp 3 at roughly 7,200m and the But we're not even talking beyond Camp 1, which sits at 6,096m. However, just because the air floating around it might be comparatively smothering in its thickness, at least compared to what we've seen so far, that doesn't mean it's not dangerous, because it is. And it does claim lives. Consider as an example the 1970 Mount Everest disaster. And yes, of course, there are multiple Mount Everest disasters, with the year not being a handy extra sprinkling of information for yourselves, but the accepted nomenclature by which we distinguish between the multiple mass casualty catastrophes that have befallen the mountain. And of course, this one happened right down on the Khumbu Icefall, specifically on the 5th of April, when a Japanese dean, the very one there to film the once-upon-a-time rather famous documentary, The Man Who Skied Down Everest, what? People have done this more than once? Were making their ascent when a huge chunk of ice around the 5,700m kind of mark just let go, an avalanche straight toward a group of load-carrying Sherpas who were ahead of the main party, killing six of them outright. And because we're not just reducing the Sherpas to background characters, their names were Mima Norbu, Mima Dore, Shering Take, Pasang, Kunga Norbu, and Kamal Shering, all of them masters of the land and experts in their trade, but just, unfortunately, lacking in that one vital mountaineering supply that Mother Nature packs for you. Luck. And for an even more modern example of the same basic horror, we can jump forward 44 years to the 2014 Everest avalanche, which again, played out right there on the Khumbu Icefall. It happened on the 18th of April, and again, as before, a huge bulge of ice hanging directly above the icefall simply broke free. We've measurements for this one, too, with the largest block of the lot estimated at being around 34.5 meters high and weighing roughly 14,000 tons. And, of course, it made straight for a team of around 25 Sherpas who were directly below, doing the oh-so-unappreciated craft that makes scaling of Everest via a metaclimber possible, hauling oxygen tanks, tents, and fuel, fine-tuning the route with ropes and ladders, and so on and so forth. When the ice hit, 16 of them were killed almost instantly, with 13 of the bodies being recovered within two days, and the final three having to be left entombed because it was simply too dangerous to dig any deeper. It was the single deadliest day on Everest, up to that point, and it was down on the Khumbu Icefall, barely even beyond base camp, a place most people have filed away as something to get out of the way so you can get on with the real climbing. As for crevasses generally, they, in simple terms, are cracks in a glacier or an ice sheet. But on Everest, they are oh-so-much more than just that, as they can often be tens of meters deep, and most terrifyingly of all, can be roofed by a thin little lid of snow that looks like everything else around it, right up until the point that someone steps on it and falls through it. The Khumbu Icefall, in particular, is absolutely riddled with them, as is the broader glacier above, up in the western quim between Camp 1 and 2. A quim just being what we'd all call a valley, by the way. However, crevasses aren't usually a problem. The bulk of them are known and monitored, and those that aren't are quite quickly added to the list when they are first discovered. For the particularly perilous ones that are in the way, too, they'll even lash together little ad-hoc bridges from ladders and leave them in situ, even including fixed ropes, just to be safe. The key word there is usually, though. Consider for a moment the death of Babu Chiri, a Sherpa. Come 2001, he was one of the juggernauts of Everest. Ten full summits to his name, a high-speed climb of the normal southern route in under 17 hours among them, and a frankly wild 1999 stunt where he spent 21 hours on the summit without supplementary oxygen. Skill, raw natural talent, a mountaineering genetic jackpot, and balls not of steel but of pure aerospace-grade titanium. These were all things which he wasn't lacking. But none of that mattered in the end, because as we've already seen so many times, his luck ran out. It was the 29th of April in the western quim on the south side route, in the 6500m slash camp 2 kind of area. He took a step on what appeared to be perfectly normal ground, and he fell through, a narrow natural bridge over the top having given way under his weight. Killed outright by the fall, his body was recovered two days later. And that's the terrifying thing about crevasses. The randomness. Sure, they aren't usually a problem. But when they are, you have no say in the matter. If they can get Chiri, they can get anyone. Tragically, too, Chiri is far from the only life claimed by Everest's glaciers. But as Namgyal Tesharing O would be able to attest, sometimes it isn't just a matter of bad luck. As he died just below camp 1 at roughly 6000m, after falling about 30m from a ladder into a crevasse, witnesses said he was not clipped into a safety line. And the obvious question there is why he wasn't on the line in the first place. Because those safety lines were very much there, and they absolutely do work when people use them. The uncomfortable answer, according to people who were actually on the mountain that season, is that some Sherpas simply didn't always bother. Early reports, pulled together by National Geographic and others, quote climbers and guides saying that it was not completely uncommon for Sherpas to just race across the ladders unclipped when they're fresh, confident and have done the same crossing a hundred times before. Clipping in and out takes a few extra seconds, and seconds matter when you're paid to be fast and efficient. And that very much brings us to something that you can basically bolt on as a secondary element to everything else we're discussing today. Complacency. As Anano Atabegasvili rather succinctly put it, while writing for the Summiter's Club, said, quote, There's a hard truth. Most Everest deaths don't happen on the way up. They happen on the way down. Summit fever is real. People push too hard, spend too long at the top, or run out of oxygen on the descent. Exhaustion steps in. So does complacency. The climb isn't over until you're safely back at base camp. Experienced guides often remind climbers, the summit is only halfway. Everest doesn't forgive mistakes, especially on the way down. And data supports that last point, too, with a 2008 report in the British Medical Journal finding that, of Everest mountaineers who died after climbing above 8,000 meters, 56% died from the descent rather than the summit. So not a huge difference, admittedly, but very much still supportive of the overall idea. On the point of complacency more broadly, however, consider the view of Alison Levine, a woman who stood on top of the world twice in her time as she wrote a whole article called Fear is Fine, but Complacency Will Kill You. It was themed around the Khumbu Icefall, incidentally, and in it she states the quote, The threat is constant, and when it comes to that icefall, there is never a time or place you feel totally safe. As a veteran of two Everest expeditions, I've probably been through the icefall 16 times, and while you would think it would become less and less frightening the more times I climbed through it, it didn't. The risk is never gone, and plenty of experienced climbers have lost their lives while going through it. I knew there was still a tremendous amount of risk present, but I focused on my surroundings. I was more agile, more able to adapt and move quickly when the ice around me moved and shifted. And this experience taught me one of the most critical lessons. Fear is fine. It's just a normal human emotion. But complacency will kill you." End quote. Now, we could go on, but you probably get the idea. The people who've actually been are very clear about the grave danger that complacency possesses. Bringing you back to the core, though, that of geographic danger, let's highlight some specific points of particular danger, starting right up near the top with the innocuous-sounding but utterly lethal Cornice Traverse. It's a short little ridge that links the South Summit, about 8,750 meters up, to the final rock barrier of the Hillary Step, then up to the True Summit. And just a quick look at the place goes some way to explaining the danger. You've got a narrow crest of snow and ice perched on a rocky spine, with roughly 2,400 meters of near-vertical southwest face dropping away to your left, and around 3,000 meters of Kangchong face disappearing into Tibet to your right. It is, by far and away, the single most exposed section of the entire ascent. And to be fair, on a good day, one where the snow is firm and the thick strokes are all behaving, most modern teams treat it as an awkward, if nerve-rattling shuffle, rather than a quite literal do-or-die flip of the coin. You clip into the line, you plant your crampons exactly where the boot track already is, and you keep your wits about you, as much as you can at that altitude anyway, placing one foot in front of another until you're through it. But on a bad day, it's warm enough that the snow under your crampons has turned to porridge, so every step is slippery, the jet stream hasn't quite behaved the way the forecast promised so the wind is brutal, and there are a few dozen people trying to squeeze through the same 50-odd meters of ridge in both directions so you don't even have elbow-river points, be it proverbially or literally. It's hardly a surprise, then, that Cornish Traverse has claimed no shortage of lives. Take as an example the 2024 deaths of British climber Daniel Patterson and his Sherpa They summited in the early hours of the 21st of May with an AK Exhibitions team, and then disappeared on the descent after an ice cornice collapsed near the Cornish Traverse. They were never found. Drop back down the mountain a bit, and there's also another section that seasoned climbers will happily rank right up there with the icefall and the Cornish Traverse for its sheer danger, the Lhotse Face, a huge blue ice wall that rears up above Camp 2, which every south-side Everest climber has to climb to reach Camp 3, and the South Coal. In dry technical terms, it's about 1,100 meters of hard glacial ice angled at around 40-50 degrees, with occasional bulges that can steepen up towards 80 degrees, cut by two rocky bands, the Yellow Band and the Geneva Spur on its upper half. And to learn about its dangers, we have only to turn to British climber Peter Legate. In 2002, he was up at Camp 3 on the Face, around 7,150 meters, riding out a truly wicked storm, before he then decided to drop back down to Base Camp to rest and regroup for another summit attempt. Then, sometime between Camps 2 and 3, he slipped on that steep blue ice in the bad weather and went sliding thousands of feet down the Lhotse Face, with his body later being found at the base. And tragically, nor is this fate an exclusive one, as back in 1996, Taiwanese climber Chen Yunnan, as part of an expedition often criticized for a string of poor decisions, became the first fatality of that season thanks to the Lhotse Face. Basically, Chen stepped out from his tent platform near Camp 3 on the Lhotse Face without wearing crampons, slipped on icy terrain, and fell into a deep crevasse. He was hauled out alive, but his condition soon deteriorated and he died before getting back to Base Camp. Top and bottom of all of this, then, when we talk about nature's deadliest obstacles on Everest, we're not just being poetic here. We're talking about very literal ambush points built into the mountain itself, be they general features found everywhere or specific named features that act as choke points. In stark contrast to the natural dangers of the mountain itself is the most unnatural element of all, man. Because, yeah, our very being there creates new perils, ones that would never be a factor if we were just to leave Everest well enough alone. Here's the photo that exemplifies it best, uploaded to Instagram on the 23rd of May 2019 by the British-Nepalese Gurkha and Special Boat Service veteran, and thus absolute weapon of a man, Nirmal Purja. It was one of two photos uploaded to celebrate his ascent to the summit the day before, and nothing more at first. I made only a passing reference to the crowd pictured. Literally, I summited Everest at 5.30am and Lhotse at 3.45pm, despite of the heavy traffic — roughly 320 people. And that was it. But then the internet saw it and collectively said, what the f**k? Much discussion then followed about the oversaturation of climbers on Everest, and what exactly that photo said about our relationship with the mountain. Within a couple of days it had jumped from Instagram to the front pages of the New York Times and the BBC, and was being held up as THE visual of a season where Nepal had issued a then-record 381 south permits, and a short, twitchy weather window had forced everyone onto the same handful of summit days, during which at least 11 people died. And that's the thing about overcrowding on Everest. It isn't just annoying. It isn't just environmentally damaging. It is dangerous. It creates new ways to die that simply wouldn't have existed if you didn't have a few hundred people all clipped into the same bit of rope up near the summit. For example, what is a queue? Well, fundamentally it's waiting about. And where are you waiting about on your final push to the summit of Everest? Well, yeah, you're waiting in the death zone, that place where you're slowly dying the entire time you're there. And that's to say nothing of the hit that it takes to your finite oxygen supply, which doesn't care if you're waiting about and doesn't care if you're pushing it hard. If that valve is open, it is trickling down at one pace or another. As Alan Arnett put it, who has been on the mountain for four separate seasons and summited once, quote, crowds, while not the only reason people die on Everest, slow a climber's pace and thus increase their fatigue and use of oxygen. He then noted that some of the people who died spent 10 or 12 hours to get to the summit and four to six hours to get back down to the South Col, end quote. In other words, a 14 to 18 hour day in one of the worst places on Earth to be hanging around. Outside Magazine boiled the problem down even more brutally. After those long, delayed summit pushes, quote, it's rare to carry oxygen for that much time. Thus, forcing the Sherpas to turn down the flow or give up their own personal supply. In plain English, if queues blow your carefully timed schedule to bits, somebody is going to run out of oxygen while still dangling off the mountain. You can see that play out in individual deaths, too, as on the 22nd of May, 2019, both Donald Cash, American, and Anjali Kulkarni, Indian, both died while descending from the summit. Cash's operator all later told reporters that she fainted with high altitude sickness after spending a long time waiting near the top, while Kulkarni's company said heavy traffic caused her death as she had to wait to descend. The Kathmandu Post was even more direct, noting that two climbers died Wednesday due to an hours-long traffic jam. In other words, then, it was the crowds that killed them. Moving beyond just the delays that overcrowding causes, however, there's also the fact that they force already narrow and difficult-to-navigate routes into one-way valves where you cannot easily flow back if you find yourself in a tangle. The summit ridge, the Hillary Step area, the balcony, the top of the Lhotse Face, these are all one-person-wide bits of ground with thousands of meters of exposure on either side, linked by a single fixed rope. And once a queue forms, you can't just step off to overtake, because off is literally a two or three kilometer fall, and neither can you quickly reverse back to safer ground if the weather takes an unpleasant turn, because there are 30 people clipped to the same line behind you. Consider also just how badly overcrowding interacts with experience. Because the days of Edmund Hillary are gone, no longer are climbers heading up Everest having to plot their specific path as they go, sussing out whether this way or that way is likely to be more perilous of the two, and having to screw in their own ropes as they go. Null. Now, today, the path is basically prefabricated for you. Sherpas and high-altitude workers go up first and stitch the whole thing together with fixed ropes and ladder bridges, then commercial outfits follow behind with long conga lines of clients whose job it is essentially to clip into the rope and shuffle after the person in front. Does that mean climbing Everest is easy? Absolutely not. And frankly, that'd be nothing if not a bold point of argumentation, given everything we've already learned. But it does mean that climbing Everest is easier now than it has been at any other point in history. And that attracts a different sort of crowd. Still plenty of bold and gallant climbers wanting to achieve the natural apex of their vertically orientated trades, certainly. But undeniably, and to be quite frank about it, simple thrill-seekers, experience collectors, and those hoping that burning some of the stacks of paper they earned in a draguey air-conditioned cube on something wild might finally get their brains to pump some serotonin for the first time since 1983. That's not just what we reckon, either. The 2020 paper, Mountaineers on Mount Everest, Effects of Age, Sex, Experience, and Crowding on Rates of Success and Death, tried to get to the bottom of, among other things, the very matter of how many Everest-summiters were inexperienced. And it concluded that, for people attempting Everest for the first time between 1990 and 2005, a mere 37.7% had experience on at least one other Nepalese or border peak. Then, between 2006 and 2018, the figure dropped further to a mere 30.7%. Flip it the other way around, and it means that something in the region of 70% of first-time Everest climbers have no recorded prior high-altitude experience on Nepalese peaks at all. However, and this is where the matter gets all the more interesting, there is a stark divide on the point of whether or not that experience is actually dangerous. And, rather shockingly, it seems that no, maybe not. Case in point, the 2022 BMJ paper, The Effects of Experience and Commercialization on Survival in Himalayan Mountaineering, retrospective cohort study by Westhoff et al. It looked at nearly 24,000 climbers in all and concluded that, after you can trial for things like route, peak, age and season, increased Himalayan experience was not associated with a change in the odds of death. And likewise, just to show that it wasn't a one-off conclusion, the penultimate paper that we mentioned, the 2021, found that, Probabilities of dying were also similar for men and women, increased for climbers about 60 and older, especially for the few that had summited, and who were independent of experience. Independent of experience basically means it has no bearing at all on whether or not it was the ghost of Hillary himself having upped the side of Everest, or a tech brat there to snap a new LinkedIn profile picture. Those facts alone didn't alter their chances of death. Then there's the climbers themselves, who, again, typically say the exact opposite, that to go up Everest lacking experience is to mark yourself for death. Going back to Alain Arnette, by way of an example, he says the following in one of his big Everest thinkpieces, quote, Everest is not for the inexperienced, the novice, or someone looking for a walk-up. There are no shortcuts. You have to put the work in before you arrive. It is hard, and people die. Base Camp is not a five-star hotel. If you come expecting a walk-up, most likely you will take advantage of that helicopter ride out, and not in a good way. And then there's Mark Jenkins, who summited Everest twice, quoting again, Too many inexperienced climbers are attempting to scale Mount Everest. A few are losing their lives. It has always been a trophy, but now that almost 4,000 people have reached its summit, some more than once, the feat means less than it did half a century ago. Today, roughly 90% of the climbers on Everest are guided clients, many without basic climbing skills. Having paid 30,000 to 120,000 to be on the mountain, too many callously expect to reach the summit. A significant number do, but under appalling conditions. All in all, you get the idea then. Specific details of how much human activity acts as a self-fulfilling ouroboros of danger may be contested. But the base idea really isn't. Everest is plenty lethal on its own, and adding people into the equation does only send the danger in one direction. And with that being all the individual ways that Everest is way more dangerous than you'd think, there is just one thing left to discover. Not the individual point-proving deaths that we've been discussing so far, but the bigger picture. The total number of deaths. According to the latest edition of Everest by the Numbers, a yearly statistical summary published by Al-AnarNet, the mountain has been summited a total of 13,737 times, by 7,563 people, up to December 2025. A tiny number, really. Not even enough people to fill a middle-sized stadium. And there's been 339 recorded deaths across Everest expedition history since 1922. And what of the bodies? Well, some do come down. If the deaths happen low enough, if the weather and terrain allow it, and if a team can be assembled without creating even more corpses in the process. But above the death zone, bringing them home very quickly stops being a question of willpower and becomes a brutally pragmatic question of physics and ethics. Because at 8,000 metres, even the act of mere walking is hard. Trying to haul a deadweight human body down fixed ropes, across ladders, over crevasses, and through bottlenecks is a whole different level of ordeal. Which is why so many, around 60% of all who ever died up there, are left where they fell. Not out of disrespect, but because the mountain makes retrieval either suicidal, ruinously expensive, or simply impossible. And so, over time, they freeze into the landscape. And then slowly get swallowed by snow, ice, and gravity until they disappear into Everest's own long memory. At least, they do in the most dignified set of circumstances. In the least dignified set of circumstances, where they never fall beneath the line of the snow, they become part of the very fabric of the mountain itself, often becoming waypoints by which future summiters find their way. Do you remember Tsiwang Pyor, the supposed identity of Green Boots? He's one of them. So too is France's Arsentiev, or as she's now known to climbers, Sleeping Beauty. And that, really, is the final indictment. The final thing you need to know to understand that Mount Everest is way more dangerous than you could possibly think. It's not the statistics buried in academic papers. It's not the dramatic tales of death and survival in the face of the very worst that nature can throw at you. But the thing is that you can look in the eyes. The person who once was full of ambition, of drive, their muscles tingling with adrenaline from the excitement of what they were about to tackle, frozen in time by the very mountain they wanted to conquer, reduced to a mere signpost for future aspirants. Thank you for watching.