The fast-track acclimatization schedule followed by Hall and most other modern Everesters is remarkably efficient: it allows climbers to embark for the summit after spending a relatively brief four-week period above 17,000 feet—including just a single overnight acclimatization excursion to 24,000 feet.* Yet this strategy is predicated on the assumption that everyone will have a continuous supply of bottled oxygen above 24,000 feet. When that ceases to be the case, all bets are off.
