IN mid-May, a record 274 persons trekking for 11 hours via Nepal scaled Mount Everest, the world’s highest peak that rises 29,031.85 feet above sea level, crossing the previous high of 223 persons reaching the summit in a single day in May 2019.
The forays to conquer the Earth’s apex summit had started way back in 1921 with the British Mt Everest Reconnaissance Expedition and it was only in 1953 — after a dozen attempts — that Edmund Hillary, a New Zealander, and Tenzing Norgay, a Nepali Sherpa, became the first persons to conquer Everest.
Indian expeditions
The decade from 1961 to 1970 saw just two successful expeditions. The first was an American mission in 1963 and the other was in 1965 when Lt Col Avtar Singh Cheema, then a Captain with the 7th Battalion of The Parachute Regiment, became the first Indian to reach the world’s highest point.
Frequency increases
In the Seventies, 17 expeditions involving 78 successful climbers were conducted. The early expeditions were largely institutional events, heavily sponsored by governments or large organisations as China and Nepal allowed only one expedition at a time.
The Eighties and Nineties saw the number of expeditions touching new heights. Nepal started issuing more permits and global tour operators and guides stepped in. It helped the Himalayan nation earn more revenue and generate employment. According to publicly available data, 2025 saw 846 successful summits, up from 834 in 2024, 636 in 2023 and 323 in 2022.
An uphill task still
“Mountaineering remains a challenge and demands high levels of physical fitness, skill and training,” says Prem Singh, a former Inspector General with the Indo-Tibetan Border Police (ITBP) who has scaled Everest twice from Nepal as well as China sides. “However, availability of better technology in terms of equipment, protection gear, access to accurate weather forecasts and enhanced administrative, logistics and support facilities in Nepal and China is encouraging more people to undertake such expeditions,” he adds.
Success rate
There have been over 13,700 successful summit ascents by 7,560 unique individuals since 1953. Many climbers, especially Sherpas, have scaled the mountain multiple times. Kami Rita Sherpa, a Nepalese guide, holds the record for having made 32 ascents.
Several Indians also hold Everest records. They include Nawang Gombu, the first man to summit twice; Santosh Yadav, the first woman to summit twice; Anshu Jamsenpa, the first dual ascent by a woman within five days; and Malavath Purna, the youngest female summiteer.
The rush to reach the Earth’s summit notwithstanding, challenges persist: inclement weather, and overcrowding in critical areas like the ‘death zone’ creating bottlenecks as well as increasing exposure to storms.
What is the death zone?
It is the area above 25,000 feet, where extreme cold, low oxygen and exhaustion can easily trigger fatal hypoxia or judgment impairment. This year, five mountaineers, including two Indians, died on Everest.
Over 350 persons have reportedly died while ascending or descending Everest. A study in the Journal of Physiology states that climbing techniques have changed, which may impact patterns of mortality. Overall, mortality rates from 1921 to 2006 versus those from 2007 to 2024 decreased from 1.4 per cent to 0.7.
“Mountaineering demands a very high level of mental and physical toughness and adaptability, and proper acclimatisation is the key,” says Ishwar Singh Duhan, a former ITBP Inspector General who has been a member of six mountaineering expeditions. “Poor acclimatisation leads to hypoxia, a condition where body organs do not get adequate oxygen, leading to severe and sometimes fatal conditions. So, in the forces, we have a structured acclimatisation process for troops to be deployed in high-altitude areas.”
The acclimatisation process is spread over 11 days. The Defence Research and Development Organisation and the Army are engaged in multi-faceted research to reduce the period. A study by Army’s medical specialists suggests that troops can be inducted from the sea-level to high-altitude areas in as little as four days if they are administered certain preventive medications such as Acetazolamide and Dexamethasone.
Typically, an expedition to Mt Everest lasts 6-8 weeks, with the acclimatisation period lasting 3-6 weeks after reaching the Everest Base Camp, where the oxygen levels are half that at sea level.
Use of Xenon gas
In May 2025, four British former Special Forces soldiers set a record by climbing Everest in under five days without acclimatising after flying in directly from London. They inhaled xenon gas to artificially pre-acclimatise their bodies to high altitudes.
According to medical literature, xenon, a colourless, inert gas, can trigger the production of hormones that increase red blood cell count and improve the body’s oxygen-carrying capacity. It is also known to have mild anaesthetic and analgesic properties, which may help mitigate altitude fatigue and pain.
A report in Scientific American speculated it was possible xenon improved the oxygen-carrying capacity. A subsequent review in High Altitude Medicine and Biology said no proof was found that inhaling the gas improves acclimatisation or shortens travel time.
