Ang Kami Sherpa is one of Nepal's most experienced "ice doctors" -- the mountaineers who brave Mount Everest's treacherous Khumbu icefall to prepare it for the climbing season -- but even he is more nervous than usual this time round.
Sherpa is among a group of ice doctors who returned to the 8,848-metre (29,029-foot) mountain in August -- four months after a huge earthquake that triggered a deadly avalanche at its base camp.
They are readying the route for the autumn season, when even in a normal year only a handful of climbers attempt the summit, most opting for the more favourable conditions of spring.
This year, Japan's Nobokazu Kuriki is the only climber planning an attempt on the summit, although a six-person support team is expected to accompany him to Camp 2, about 6,400 metres high and usually around two days of trekking beyond base camp.
At 63, Sherpa is more familiar with Everest than most, having kicked off his mountaineering career in 1975 when he assisted Japan's Junko Tabei in her successful bid to become the first woman to summit the peak.
But this time, the veteran ice doctor says even he is worried after April's quake, which killed nearly 9,000 people, 18 of them on the world's highest peak.
"Our job is more difficult this year, the mountain has changed (after the quake)," Sherpa told AFP by phone from Everest base camp, where the ice doctors have already begun work.
"There is always a risk up here but we are a little more scared this year."
Highly-skilled mountaineers like Sherpa are the first men on the peak every season, using ropes and ladders to build a route across plunging crevasses and constantly shifting ice.
This year the dangers are even higher than usual with Nepal still experiencing regular aftershocks, further increasing the risk of avalanches.
The avalanche that hit on April 25 was the second in as many years after 16 Nepali guides lost their lives on the icefall in 2014, sparking a shutdown of the peak.
- Aftershocks and avalanches -
Many in the mountaineering community question the wisdom of asking the elite climbers to brave aftershocks and avalanches for the sake of a single summit hopeful.
An ice doctor can earn $3,500 in a season, sometimes more in tips from foreign mountaineers, a large sum in a country where the average annual income is about $705.
Mountaineering is a huge revenue earner for impoverished Nepal, home to eight of the world's 14 peaks over 8,000 metres.
Everest alone attracts hundreds of climbers during the April to May spring season, when weather conditions are deemed ideal.
Ang Dorjee Sherpa, president of the Sagarmatha Pollution Control Committee (SPCC), which manages the peak, said there was no option but to send the route-setters up once the government issues a permit for the mountain.
"It is our job to set the route, regardless of the number of climbers," he told AFP.
"Tourism as a whole has suffered a downfall, at least if there is an Everest summit this year, it will help send out a positive message."
- 'Backbone of mountaineering' -
Every day the ice doctor and his team set off from base camp before dawn, often working for over 12 hours at a stretch.
Although Sherpa developed his skills on the job, in recent years, ice doctors have enrolled at the nearby Khumbu Climbing Center, set up by US mountaineer Conrad Anker in memory of renowned alpinist Alex Lowe who died in 1999.
"The ice doctors know the mountain the best, they are highly experienced," said Ang Tshering Sherpa, president of Nepal's mountaineering association.
"They are the backbone of mountaineering on Everest, all other climbs depend on the initial risk they take."
US veteran mountaineer and Everest expert Alan Arnette said days get shorter and colder as winter approaches, making summits less likely.
"Spring Everest expeditions have a 66 percent success (rate) compared to 29 percent in the autumn," Arnette told AFP.
Nevertheless, Japanese climber Kuriki said he was determined to climb in the autumn and hoped to summit in mid-September.
Kuriki's last attempt on Everest in autumn 2012 ended when he needed to be rescued from Camp 2, and he eventually lost nine of his fingers to frostbite.
As he ascends, the ice doctors will continue to monitor the route, watching the clock anxiously until he returns.
"I have done this for so many years, but this year feels different somehow," ice doctor Sherpa said.
"We hope that nothing will happen."