An internal-frame pack carries its support structure — stays, framesheets, or rods — inside the pack body, hugging the load close to your back for stability on uneven terrain. The dominant modern backpack design, it excels at balance for scrambling, skiing, and rough trails, though it ventilates less than an external frame.
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.
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.
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.
Verglas is a thin, often nearly invisible coating of ice that forms on rock when rain or melting snow freezes onto a cold surface. It makes rock treacherously slick and is too thin to climb on with tools, turning easy terrain into a serious hazard. Verglas is a notorious feature of alpine and winter conditions.
An objective hazard is a danger in the mountains that exists independently of the climber's skill — such as rockfall, avalanches, serac collapse, crevasses, and storms. Unlike subjective hazards (errors you control), objective hazards can only be avoided or minimized through route choice, timing, and judgment, not skill alone.
In mountaineering, exposure usually means the degree to which a position has a big drop below it — exposed terrain has serious fall consequences even when the moves aren't hard, demanding composure. 'Exposure' is also used for the body's dangerous exposure to cold and weather, which can lead to hypothermia.
A whiteout is a weather condition in which falling or blowing snow and flat light erase all visual contrast, so the ground, horizon, and sky blend into uniform white. Hikers and mountaineers can lose all sense of direction and slope, making navigation by map, compass, and GPS essential and travel hazardous.
Step-in (automatic) crampons attach with a wire toe bail and a heel lever, clipping on like a ski binding. They give the most secure, precise fit but require stiff boots with both a toe and a heel welt. They are the standard for technical ice and steep mountaineering on fully rigid B3 boots.