- Specialist climbers begin work to reopen Mount Everest to climbers after earthquake
- Mountaineering expeditions given permits to climb in Nepal
- Japanese climber becomes the first mountaineer to return to Everest after killer avalanche
(CNN)The "icefall doctors" are back on the world's highest mountain.
They're preparing for the first climber to ascend Everest since Nepal's devastating earthquake in April. And he's likely to be the only mountaineer to do the climb this season.
The specialist team of five Nepalese Sherpas is resetting the route between Everest's Base Camp at 5,970 meters (17,600 feet), across the notorious Khumbu icefall, to Camp 2 at 6,500 meters (21,300 feet), which was swept away in a deadly avalanche set off by the huge tremor.
The crack team of route setters earns just $4,500 per season to keep climbers safe, living on the mountain up until November, when the season closes due to extreme cold and strong winds.
The Khumbu icefall -- a steep portion of a glacier shaped like a frozen waterfall -- is one of the most treacherous sections of a route used to summit the 8,850 meter (29,029 feet) mountain, and it's the Sherpas' job to find a safe path across the heavily crevassed Khumbu glacier.
They build bridges using aluminum ladders to cross deep crevasses and set ropes for mountaineers to clip their harnesses into over dangerous sections.
The constantly moving glacier means the ice is under tremendous pressure. Even the safest route might break up without warning, so these so-called icefall doctors stay on location until the end of the climbing season to maintain the ropes and ladders.
The team has already surveyed this season's route and set ladders in place.
Crossing lightweight bridges over seemingly bottomless blue crevasses is an adrenaline rush -- made harder as they're slippery with ice -- and wearing crampons feels like you're wearing stilettos, not mountaineering boots.
Ang Tsering Sherpa, a 41-year mountaineering veteran and President of Nepal's Mountaineering Association, says the autumn season on Everest is short and the icefall doctors will decide when it should end any time after October 8.
"The snow conditions are very stable and the icefall doctors are very experienced, they know the conditions very well and they know each step very well. Their main priority is to put the safety and security of mountaineers and themselves first," he told CNN.
The Nepal government closed Everest after the devastating April 25 earthquake triggered massive avalanches on the mountain killing 19, and injuring 61 others. Many of those were sheltering in the comparative safety of Base Camp.
A massive helicopter and land rescue mission was needed to rescue around 230 mountaineers stranded on the mountain when the icefall doctors' route was destroyed.
The Spring 2015 climbing season was then abandoned -- and for the first time in more than four decades, no climbers summited Everest that season.
Tourism is an important source of income for Nepal. According to the World Travel and Tourism Council it accounted for 8.2% of GDP in 2013.
Nepal is home to eight of the 10 highest mountains in the world, so mountaineering is a significant source of revenue, employing large teams of Sherpas, guides and porters to support groups of climbers.
Nepal's government is keen to see mountaineers and tourists return to help rebuild its economy. It has already granted approval to nine mountaineering expeditions, with a further four in the approvals process.
Only one is approved to climb Sagarmatha -- the local name for Mount Everest.
Japanese climber Nobukazi Kuriki, 33, from Hokkaido, is already acclimating in the region.
He's planning a summit assault in mid September.
Sherpa says the icefall doctors are preparing the way for his climb but warned that Kuriki needs to have completed his expedition by early October.
It'll be Kuriki's fifth attempt to climb Everest and he plans to climb solo, without oxygen. What makes Kuriki's attempt even more remarkable is that he lost most of his fingers and a thumb to frostbite in a previous attempt.
For the icefall doctors, the autumn season is business as usual making the route as safe as they can for Kuriki.
The Japanese adventurer may be the only expedition on Everest this season as few expeditions choose this extreme and short season to climb, preferring to try for the summit in spring. When the Sherpa repair team decide conditions have become too cold and too extreme, mountaineering on Everest will end until the following spring.