Editing Death zone (section)

{{Short description|Altitudes above about 8,000 m (26,000 ft)}}
{{Other uses|Zone of Death (disambiguation){{!}}Zone of Death}}
[[File:Hillary Step near Everest top (retouched).jpg|thumb|The summit of [[Mount Everest]] lies in the death zone.]]
In [[mountaineering]], the '''death zone''' refers to altitudes above which the pressure of [[oxygen]] is [[Effects of high altitude on humans|insufficient to sustain human life]] for an extended time span. This point is generally considered to be {{cvt|8000|m|ft|-2}}, where atmospheric pressure is less than {{convert|356|mbar|inHg psi}}.<ref name="PBS">{{cite web
|url= https://www.pbs.org/wgbh/nova/transcripts/2506everest.html|title= Everest: The Death Zone| work=Nova|publisher= PBS|date= 1998-02-24}}</ref> The concept was conceived in 1953 by [[Edouard Wyss-Dunant]], a Swiss doctor, who called it the '''lethal zone'''.<ref>{{cite journal |journal= The Mountain World |year=1953 |pages=110–117|title= Acclimatisation |last=Wyss-Dunant|first=Edouard |url=https://archive.org/details/mountainworld195029881mbp |format=PDF |access-date=March 10, 2013 }}</ref> All [[eight-thousander|14 peaks above 8000 m]] (the "eight-thousanders") in the death zone are located in the [[Himalaya]] and [[Karakoram]] regions of Asia.

Many deaths in high-altitude mountaineering have been caused by the effects of the death zone, either directly by the loss of vital functions or indirectly by poor decisions made under stress (e.g., not turning back in deteriorating conditions, or misreading the [[climbing route]]), or physical weakening leading to accidents (e.g., falls). An extended stay above {{cvt|8000|m|ft|-2}} without [[Bottled oxygen (climbing)|supplementary oxygen]] will result in deterioration of bodily functions and death.<ref name="PBS"/><ref name=Huey>{{Cite journal|url=http://jeb.biologists.org/content/204/18/3115.abstract|title=Limits to human performance: elevated risks on high mountains|first1=Raymond B.|last1=Huey|first2=Xavier|last2=Eguskitza|date=2 July 2001|journal=Journal of Experimental Biology|volume=204|pages=3115–9|pmid=11581324|issue=18|doi=10.1242/jeb.204.18.3115|bibcode=2001JExpB.204.3115H |url-access=subscription}}</ref><ref name=Grocott>{{cite journal|journal=N Engl J Med|year=2009|volume=360|pages=140–9|title=Arterial Blood Gases and Oxygen Content in Climbers on Mount Everest|first1=Michael P.W.|last1=Grocott|first2=Daniel S.|last2=Martin |first3=Denny Z.H.|last3=Levett |first4=Roger|last4=McMorrow |first5=Jeremy|last5=Windsor |first6=Hugh E. |last6=Montgomery|doi=10.1056/NEJMoa0801581|pmid=19129527|issue=2}}</ref>