Pressure cookers use at high altitudes

A pressure cooker is often used to compensate for the low atmospheric pressure at a very high elevation. Under these circumstances water boils at temperatures significantly below 100 °C (212 °F) and, without the use of a pressure cooker, may leave boiled foods undercooked, as described in Charles Darwin's The Voyage of the Beagle (chapter XV, March 20, 1835):

Having crossed the Peuquenes [Piuquenes], we descended into a mountainous country, intermediate between the two main ranges, and then took up our quarters for the night. We were now in the republic of Mendoza. The elevation was probably not under 11,000 feet [...]. At the place where we slept water necessarily boiled, from the diminished pressure of the atmosphere, at a lower temperature than it does in a less lofty country; the case being the converse of that of a Papin's digester. Hence the potatoes, after remaining for some hours in the boiling water, were nearly as hard as ever. The pot was left on the fire all night, and next morning it was boiled again, but yet the potatoes were not cooked.

Lightweight pressure cookers as small as 1.5 litre weighing 1.28 kg are available for mountain climbers. Sherpas often use pressure cookers in base camp.