What Is the Vertical Limit in Mountain Climbing?

The “vertical limit” is defined as the highest altitude at which humans can survive. This altitude is generally understood to be approximately 18,000 feet above sea level. If humans spend time above this altitude, their health gradually declines due to a lack of oxygen and lower barometric pressure. Altitudes above approximately 25,000 feet are called the Death Zone, meaning that, in addition to an even greater lack of oxygen, mountain climbers also face a greater chance of frostbite, hypothermia and potentially fatal swelling of blood vessels, especially in the brain.

Why It’s Dangerous

Without acclimation to the altitude, mountain climbers above the vertical limit can expect to experience significant problems with tiredness and lethargy, dizziness, headaches, nausea and shortness of breath. These symptoms can be mitigated somewhat by following recommendations for maximum rates of ascent and resting at the high altitude for 24 to 48 hours. Careful weight gain before climbing to such heights can help counteract the physiological decline and weight loss associated with extended periods at such altitudes. However, climbers at even higher altitudes in and approaching the Death Zone might need supplemental oxygen to combat the more extreme symptoms associated with even less oxygen and barometric pressure.

Basic Ways to Counteract Illness at High Altitudes

What Is the Max Altitude at Which a Person Can Breathe?

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The basic way to acclimate to new altitudes is to avoid overexertion for several hours or days to allow the body to adjust. Mountain climbers also use such maxims as “Climb high and sleep low,” meaning it is usually acceptable to climb to higher altitudes as long as the climber descends to lower altitudes to sleep, and “Don’t go up until symptoms go down,” meaning to stop climbing if symptoms occur. Proper hydration and eating carbohydrates can also help mountain climbers to avoid or mitigate symptoms.

Popular High Altitude Mountain Climbing Destinations

Despite the risks, many people continue to pursue high altitude mountain climbing in countries around the world. Perhaps the most famous destination is Mount Everest in Nepal, with a peak just over 29,000 feet. Mount Kilimanjaro in Tanzania is the highest peak in Africa at more than 19,000 feet. Mount McKinley in Denali, Alaska, is the highest peak on the North American continent at over 20,000 feet. Late spring or early summer is often the best time for climbing such peaks to lessen the threat of injury or death due to avalanches or dangerous crevasses.

Proper Equipment and Guidelines

Altitude Sickness & Joint Aches

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Mountain climbers should be in peak physical and mental condition, both for their own safety and the safety of their team. Each climber will need to carry all his own equipment, including appropriate cold weather gear and shelter, as well as a portion of the group’s equipment. Oxygen saturation in the air can drop from 21 percent to 14.5 percent as a person travels from sea level to 10,000 feet, with even greater drops at higher altitudes. So depending upon the climber’s physiology and acclimatization time, portable oxygen tanks might be advisable. Most of all, mountain climbers should follow the advice of local authorities, guides, more experienced hikers and their own good judgement when undertaking such physically demanding and dangerous climbs.