Summit fever is the dangerous, single-minded determination to reach a summit despite worsening weather, late timing, exhaustion, or other warning signs that should prompt a retreat. A psychological hazard rather than a physical one, summit fever has contributed to many mountaineering accidents by overriding the discipline to turn around.
Pressure breathing is a technique for high altitude in which you exhale forcefully against slightly pursed lips, raising the pressure in your lungs to improve oxygen uptake from thin air. Rhythmically synced with the rest step, it helps climbers stave off breathlessness and altitude symptoms while moving steadily uphill.
Supplemental oxygen is bottled oxygen, delivered through a mask and regulator, that high-altitude climbers breathe to offset the thin air on the world's highest peaks. Used widely above about 7,000-8,000 metres, it reduces the risk of altitude illness and frostbite and aids performance, though some climbers ascend the 8,000ers without it.
A snow bollard is an anchor carved directly from the snow itself — a teardrop- or horseshoe-shaped mound or trench around which the rope is looped to belay or rappel. Needing no hardware, it's a valuable backcountry anchor when gear is unavailable, but its strength depends entirely on snow quality and careful construction.
A high camp is a camp established above base camp, higher on the mountain, used to break a big climb into stages and to launch the summit bid from closer to the top. Expeditions often set a series of numbered camps (Camp 1, 2, 3) for acclimatization and to shorten the final summit day.
Base camp is the main, established camp at the foot of a mountain or expedition objective, serving as the hub for the climb. Stocked with supplies, tents, and often communications and medical support, base camp is where climbers rest, acclimatize, and stage their pushes to higher camps and the summit.
The rest step is an energy-saving uphill walking technique for steep snow and altitude, where you briefly lock the trailing leg straight and pause on the skeleton between each step, letting the muscles rest for a moment. Combined with rhythmic pressure breathing, it lets mountaineers move steadily for hours without exhausting their legs.
A running belay is the protection method used in simul-climbing: both climbers move at once with several pieces of protection clipped between them, so the rope runs through gear that would catch a fall even though no one is statically belaying. It keeps a moving team protected while maximizing speed.
Simul-climbing (simultaneous climbing) is a speed technique where both the leader and follower climb at the same time while tied to the same rope, with protection placed between them, rather than one belaying the other. It is much faster than pitching but riskier, since a fall by either climber can pull the other, so it's reserved for easier terrain or experienced teams.
A via ferrata ('iron road') is a protected climbing route equipped with fixed steel cables, rungs, ladders, and bridges that let people travel exposed mountain terrain with relative safety. Climbers clip a special via ferrata lanyard to the cable for protection. It bridges hiking and climbing and is hugely popular in the Alps.