Mountaineers on Mount Everest: Effects of age, sex, experience, and crowding on rates of success and death

Abstract

Mount Everest is an extreme environment for humans. Nevertheless, hundreds of mountaineers attempt to summit Everest each year. In a previous study we analyzed interview data for all climbers (2,211) making their first attempt on Everest during 1990-2005. Probabilities of summiting were similar for men and women, declined progressively for climbers about 40 and older, but were elevated for climbers with experience climbing in Nepal. 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 were independent of experience. Since 2005, many more climbers (3,620) have attempted Everest. Here our primary goal is to quantify recent patterns of success and death and to evaluate changes over time. Also, we investigate whether patterns relate to key socio-demographic covariates (age, sex, host country, prior experience). Recent climbers were more diverse both in gender (women = 14.6% vs. 9.1% for 1990-2005) and in age (climbers � 40 = 54.1% vs. 38.7%). Strikingly, recent climbers of both sexes were almost twice as likely to summit-and slightly less likely to die-than were comparable climbers in the previous survey. Temporal shifts may reflect improved weather forecasting, installation of fixed ropes on much of the route, and accumulative logistic equipment and experience. We add two new analyses. The probability of dying from illness or non-traumas (e.g., high-altitude illness, hypothermia), relative to dying from falling or from 'objective hazards' (avalanche, rock or ice fall), increased marginally with age. Recent crowding during summit bids was four-fold greater than in the prior sample, but surprisingly crowding has no evident effect on success or death during summit bids. Our results inform prospective climbers as to their current odds of success and of death, as well as inform governments of Nepal and China of the safety consequences and economic impacts of periodically debated restrictions based on climber age and experience.

Death Zone Weather Extremes Mountaineers Have Experienced in Successful Ascents

“…BP’s positive correlation with Temp and negative correlation with Wind recorded for non-winter ascents of Everest and K2 supported the proposal by Moore and Semple (2011 , 2012) for Everest climbers that summit BP can act as a simple and easily implementable predictor of the risk of hypothermia and frostbite. Huey et al (2020) suggested that improved weather forecasting was one reason for the increased likelihood of summiting Everest and the lower likelihood of mountaineers dying over the past 15 years compared with 1990–2005. Therefore monitoring of Temp and BP in the base camp and at higher camps, as during the first Everest expeditions almost 100 years ago ( Moore et al, 2010 ), should become standard practice to correct more general forecasts for high-altitude expeditions.…”

Into Thick(er) Air? Oxygen Availability at Humans' Physiological Frontier on Mount Everest

“…Everest's upper slopes ( Matthews et al, 2020 ). Added impetus for this development may be provided if future research determines that oxygen availability has a detectable influence on mountaineering success and safety, perhaps including for those climbing with supplemental oxygen ( Fontanarosa et al., 2000 ; Huey et al., 2020 ).…”

Urological Emergencies and Diseases in Wilderness Expeditions

“…10 One example for an expedition setting in which this issue relevant is Mount Everest, where approximately 1000 people ascend each year, with 54% of Everest climbers from 2006 to 2019 being ≥40 y old and 85% being male. 11 Considering these demographics, there is a reasonable likelihood that a few climbers per year experience acute urinary retention related to BPH as they attempt to summit the peak.…”