Couloir in the context of Fleischbank

Ice climbing is a climbing discipline that involves ascending routes consisting entirely of frozen water. To ascend, the ice climber uses specialist equipment, particularly double ice axes (or the more modern ice tools) and rigid crampons. To protect the route, the ice climber uses steel ice screws that require skill to employ safely and rely on the ice holding firm in any fall. Ice climbing routes can vary significantly by type, and include seasonally frozen waterfalls, high permanently frozen alpine couloirs, and large hanging icicles.

Ice climbing originated as a subdiscipline of alpine climbing, where sections of scalable ice are encountered alongside segments instead necessitating rock or mixed climbing. Ice climbing arose as an independent sport in the 1970s. Modern ice climbing includes a difficulty grading system peaking at WI6 to WI7, as ice tends to hang vertically at its most severe. WI7 is very rare and usually attributed to overhanging ice with serious risk issues (i.e. unstable ice, little protection, and a risk of death). Mixed climbing has pushed the technical difficulty of ice climbing routes by crossing bare rock overhangs and roofs. This can entail dry-tooling, the use of ice tools on bare rock.

Thamserku is a mountain in the Himalayas of eastern Nepal. The mountain is connected by a ridge leading eastward to Kangtega. Thamserku is a prominent mountain to the east of Namche Bazaar and lies just north of Kusum Kangguru.

The first ascent was made in 1964 from the south by members of Edmund Hillary's Schoolhouse Expedition: Lynn Crawford, Pete Farrell, John McKinnon and Richard Stewart. Below the basin on the southwest face, they reached the south ridge after climbing a difficult couloir. The team described the climb as difficult and the route has never again been repeated in its entirety. In 2014, Russian climbers Alexander Gukov and Alexey Lonchinskiy made the first ascent on the southwest face.

The Bottleneck is a location along the South-East Spur (also known as Abruzzi Spur), the most-used route to the summit of K2, the second-highest mountain in the world, in the Karakoram, on the border of Pakistan and China.

The Bottleneck is a narrow couloir, which is overhung by seracs from the ice field east of the summit. The couloir is located only 400 m (1,300 ft) below the summit, and climbers have to traverse about 100 m (330 ft) exposed to the seracs to pass it. Due to the height of 8,200 m (26,900 ft), and the steepness of 50 to 60 degrees, this stretch is the most dangerous part of the route. According to AdventureStats, 13 out of the last 14 fatalities on K2 have occurred at or near the Bottleneck.

Alpine climbing (German: Alpinklettern) is a type of mountaineering that uses any of a broad range of advanced climbing techniques, including rock climbing, ice climbing, and/or mixed climbing, to summit typically large rock, ice, or snow covered climbing routes (e.g. multi-pitch or big wall climbs) in mountainous environments. While alpine climbing began in the European Alps, it is now used to refer to such climbing in any remote mountainous area, including in the Himalayas and Patagonia. The derived term alpine style refers to the fashion of alpine-climbing to be in small lightly-equipped teams who carry all their equipment (e.g. no porters are used), and do all of the climbing themselves (e.g. no sherpas or reserve teams).

In addition to the specific risks of rock, ice, and mixed climbing, alpinists face a wide range of serious additional risks. This includes the risks of rockfalls (common with rock faces in alpine environments), of avalanches (especially in couloirs), of seracs and crevasses, of violent storms hitting climbers on exposed mountain faces, of altitude effects (dehydration, edema, frostbite), of complex navigation and route finding, of long dangerous abseils, and of the difficulty of rescue and/or retreat due to the remoteness of the setting. Due to the large length of alpine routes, at times, alpinists need to move simultaneously to maintain speed (e.g. simul climbing or as rope teams), which brings another source of serious risk.