Reaching the top of Mount Everest - the highest point on the planet at 29,028 feet - is a feat only about 5,000 people have accomplished. The trek to the summit takes months of physical preparation and weeks of acclimatization to get climbers used to the mountain's oxygen-starved altitudes.
"There seems to be a disaster mystique around Everest that seems to only serve to heighten the allure of the place," filmmaker and director Jennifer Peedom, who has climbed Everest four times, previously told Business Insider.
Here's what it's like to climb the world's highest peak, according to 10 people who've experienced Everest.
Ronald Crystal, a 77-year-old doctor from New York, said that to get ready for Everest, he did three personal training sessions per week and regularly climbed the 34 floors up to his Manhattan apartment wearing his pack and mountaineering boots.
Most climbers and their Sherpa guides stock up on supplies in Kathmandu, the capital of Nepal, before the climb. From there, they take a 25-min puddle-jumper plane to Lukla airport.
From Lukla, climbers trek 40 miles to the foot of the mountain. This often takes two weeks, since climbers need to acclimatize to the high-altitude environment.
Base Camp rests on a large glacier, and even staying there can be treacherous. "According to my trekking guide, the glacial terrain changes so rapidly that the expeditioners have to move their tents every two weeks," Sprayregen wrote.
Kami Rita Sherpa holds the world record for Everest summits: 24.
"I'm going back next year," Sherpa said.
Base Camp sits at an elevation of 17,600 feet, which is high enough to cause health complications. On his second day there, Crystal developed a dangerous lung problem and used his medical expertise to save his own life.
Mountaineers typically spend one to two months at Base Camp, making multiple trips up and down the mountain to acclimatize.
During each expedition from Base Camp, climbers must navigate the dangerous Khumbu Icefall. Kami Rita Sherpa said he gets especially nervous during this part of the climb.
In 2005, climber Shaunna Burke and her partner at the time, Ben Webster, were climbing near the Khumbu Icefall when Webster fell and broke his leg. "I heard him scream my name at top of his lungs," Burke said. "I stopped dead in my tracks. I knew by sound of his voice that something bad had happened."
Webster had stepped on an errant piece of ice that sent him flying sideways. He nearly fell into a deadly crevasse, but stopped himself by wedging his elbows sideways. The fall snapped his tibia and fibula.
Burke said sleeping at the higher camps is almost impossible. "Every second or third breath your body gasps for air, and you wake yourself up," she said.
The debilitating conditions at high altitudes are what makes mountaineering unique, Burke said. "Typical athletes are building up to game day — they're mentally tougher and bodies stronger and more energized," she said. "Whereas in mountaineering, on summit day, your muscles are atrophied, you have insomnia, you're exhausted."
When Everest warms in April and May, there are often just a few good windows of hiking weather. Everybody wants to summit during those critical days, which can lead to lines at the top.
Instead, Sherpa said deaths on Everest happen after climbers inadvertently push their bodies past their limits, which makes it hard to climb back down. "When returning, their body is out of energy, and many people die due to this cause," he said.
Lhakpa Sherpa, who has reached the summit more times than any other woman, previously told Business Insider that climbers can suffer from an oxygen-starved delirium in the death zone. "Their life is in our hands and we must protect them from their own insanity," she said.
"Your body is breaking down and essentially dying," Burke said of the death zone. "It becomes a race against the clock."
The trek from Camp Four to the summit adds 2,500 feet in elevation. It takes about seven hours. Lhakpa Sherpa said this is by far the most difficult day of the journey.
On the way up, climbers pass corpses of fallen hikers. Lhakpa Sherpa said she saw seven bodies last year. One stuck in her mind. "He looked alive, because the wind was blowing his hair," Sherpa said.
Sherpa said she carries out special summiting rituals. "I talk with the mountain," she said, "very quiet." She also meditates, envisioning the successful climb and telling the mountain not to kill her.
Reaching the summit, Lhakpa Sherpa said, is an unparalleled feeling. "I feel like a zombie who has stumbled into heaven. At the summit, I truly feel on top of the world," she said. "A euphoria I cannot find anywhere else."
"The summit is only halfway," Burke said. "Your ultimate goal should be to make it back to camp alive."
Crystal said he is glad he attempted to climb Everest, even though he didn't get close to the summit. "It doesn't really matter what your age is, it doesn't matter whether you really reach the goal, its having the goal and working toward the goal that's the important part," he said.