The Hillary Step is dangerous because it combines a steep, exposed scramble with the worst physiological conditions on Earth. Sitting at 8,770 meters, just 80 meters below Everest’s summit, it forces climbers to navigate a near-vertical obstacle at an altitude where the body is rapidly deteriorating, oxygen is critically scarce, and a single misstep means a fatal fall down one of the mountain’s massive faces.
What the Hillary Step Actually Looks Like
The original Hillary Step was a 20-meter vertical mixture of rock, ice, and hard snow, first climbed by Edmund Hillary and Tenzing Norgay in 1953. It sat on a narrow ridge with enormous exposure on both sides: the Southwest Face dropping away to the left, the Kangshung Face to the right. There was no easy way around it.
After Nepal’s 7.8-magnitude Gorkha earthquake in 2015, the step partially collapsed. Mountaineer Tim Mosedale reported the change after climbing that season, though Nepal’s Mountaineering Association initially disputed it. What climbers encounter today is no longer a sheer rock wall but a steep 45-to-60-degree snow and ice ramp. Expedition guides now commonly call it the “Hillary Slope.” The terrain is less technically demanding than the original rock face, but the exposure and altitude haven’t changed, and the ramp introduces its own risks: ice collapses and unstable footing on steep snow.
Your Body at 8,770 Meters
At the altitude of the Hillary Step, atmospheric pressure is roughly a third of what it is at sea level. Your blood carries so little oxygen that the arterial partial pressure drops below 30 torr, a level that would render most people unconscious in a hospital setting. The body compensates by hyperventilating to an extreme degree, which strips carbon dioxide from the blood and pushes arterial pH above 7.7, a state of severe alkalosis. Maximum oxygen uptake falls to about one liter per minute, compared to three or four liters for a fit person at sea level.
What this means in practical terms: your muscles have barely enough fuel to move. Your brain is starved of oxygen, slowing reaction time, impairing judgment, and degrading fine motor control. Climbers at this altitude describe feeling drunk or confused. Now add a technical climbing obstacle that requires you to find handholds, test them, and pull yourself upward while wearing bulky high-altitude boots and crampons. The mismatch between what the terrain demands and what your body can deliver is the core of the danger.
The Climbing Difficulty in Context
The original Hillary Step was rated Class 4, which in climbing terms means simple climbing with serious exposure where falls can cause severe injury or death. Class 4 terrain requires you to actively search for handholds and use your upper body. At lower elevations, most experienced climbers would handle it without much trouble. At nearly 8,800 meters, wearing crampons on rock and ice, with gloved hands and an oxygen mask limiting your field of vision, Class 4 becomes something entirely different. The margin for error shrinks to almost nothing.
Fixed ropes are the primary safety system. Sherpa crews install lines before the climbing season begins, and these cables are the lifeline for hundreds of climbers passing through the Death Zone each season. As of 2026, protocols require dual fixed lines, one designated for ascending traffic and another for descending, specifically to address the bottleneck problem that plagued the step for decades.
Bottlenecks and Time Exposure
Before dual fixed lines were standard, a single rope served both directions. Climbers heading up had to wait for descending climbers to pass, and vice versa. On busy summit days, this created traffic jams lasting an hour or more at nearly 8,800 meters. Every minute spent standing still in the Death Zone burns through supplemental oxygen supply, increases the risk of frostbite, and pushes climbers closer to the point where their bodies simply stop functioning.
The weather compounds this. During the May climbing season, wind speeds near the summit average around 12 meters per second (about 27 mph), with gusts recorded as high as 27 meters per second (60 mph). Wind chill temperatures average around minus 40°C, with extremes reaching minus 57°C. At those wind chills, exposed skin can develop frostbite in roughly seven minutes. A climber stuck in a queue at the Hillary Step, clipped to a fixed rope on an exposed ridge, has no shelter from any of this.
Fatal Falls and Collapses
The ridge near the Hillary Step has been the site of multiple fatalities over the decades. The exposure on both sides means any fall is likely unsurvivable. In one incident reported by Outside Online, an ice ledge collapsed and sent six climbers sliding down the north slope. Four were rescued, but two continued sliding toward a sheer drop. A witness described the scene: “Two people were sliding to their deaths. And it was silent.” One of the victims was a Nepali guide named Pas Tenji Sherpa, who had been standing on the summit just minutes earlier without supplemental oxygen, wearing a white baseball cap in what had seemed like calm conditions.
These incidents highlight a cruel feature of the Hillary Step’s location. Climbers reach it when they are at their most exhausted, either on the final push to the summit or during the descent when energy reserves are nearly gone. The terrain doesn’t care that you’ve been climbing for 12 hours or that your oxygen bottle is running low. It demands the same level of attention and physical control regardless.
Why Descent Is Often Worse
Most Everest fatalities happen during the descent, and the Hillary Step is a major reason. Going up, climbers are motivated and relatively fresh compared to their return trip. Coming down, they’ve spent hours above 8,000 meters, their cognitive function is further degraded, and they face the technical challenge of downclimbing steep terrain while fighting exhaustion. Rappelling in crampons on a snow-and-ice ramp, with numb hands and impaired balance, is where the combination of altitude physiology and technical difficulty becomes most lethal.
The fixed ropes help, but they aren’t foolproof. Climbers must unclip and reclip at anchor points, a process that requires dexterity and attention. In severe cold, with thick gloves and hypoxic confusion, even this routine action becomes a moment of vulnerability where you are briefly unattached to anything on a ridge with thousands of meters of empty air on either side.