Sports

# How high is the Armstrong limit?

By: Julie ArnottUpdated: November 13, 2020

#### Site Statistics

• Questions
94,481
1,984,101
• Categories
21
• Last Updated
May 20, 2022
On Earth, the limit is around 18–19 km (11–12 mi; 59,000–62,000 ft) above sea level, above which atmospheric air pressure drops below 0.0618 atm (6.3 kPa, 47 mmHg, or about 1 psi). The term is named after United States Air Force General Harry George Armstrong, who was the first to recognize this phenomenon.

Also to know is, what the lowest pressure a human can survive?

Disregarding hypoxia, the lowest atmospheric pressure the human body can withstand is around 6 percent sea level pressure, or 61.8 millibars, below that pressure the water and blood in your body starts to boil.

Why does your blood boil at high altitude?

When atmospheric pressure is lower, such as at a higher altitude, it takes less energy to bring water to the boiling point. Less energy means less heat, which means water will boil at a lower temperature at a higher altitude.

What is Ebullism?

Ebullism, formation of bubbles in the bodily fluids because of an extreme reduction in the surrounding pressure. Aircraft pilots are susceptible to ebullism when they venture into the upper atmosphere; the higher the pilot goes, the lower the surrounding pressure becomes.

How high can you go without oxygen?

We pass out when the pressure drops below 57 percent of atmospheric pressure — equivalent to that at an altitude of 15,000 feet (4,572 meters). Climbers can push higher because they gradually acclimate their bodies to the drop in oxygen, but no one survives long without an oxygen tank above 26,000 feet (7925 m).

## Related

### What is the elevation of the Death Zone?

The term 'death zone' is often used in reference to an altitude above 26,000 feet beyond which many researchers believe human life can no longer adequately acclimatize on its own to. At 17,600 feet (Base Camp), the partial pressure of oxygen (pO2) is approximately half of its value at sea level.

### What temperature does water boil at the Dead Sea?

Pure water boils at 100 degrees Celsius under normal atmospheric pressure, but the Dead Sea surface is so low (more than 400 meters below "sea level") that water boils at about 101 degrees there.

### Can your blood actually boil?

Boiling blood
In space, there is no pressure. So the boiling point could easily drop to your body temperature. That means your saliva would boil off your tongue and the liquids in your blood would start to boil.

### At what altitude does water boil at room temperature?

At sea level, water boils at 100 °C (212 °F). For every 500-foot (150 m) increase in elevation, water's boiling point is lowered by approximately 0.5 °C. At 8,000 feet (2,400 m) in elevation, water boils at just 92 °C (198 °F).

### What would happen if you boil blood?

If the liquid in your blood stream started boiling, it would turn into gas that would make your skin swell. NASA makes it clear that your body wouldn't explode and your eyes wouldn't pop out of your head like many science fiction movies suggest. However, you would swell up and get really painfully puffy.

### At what temp does blood boil?

At an altitude of 63,000 feet (19,000 m), it boils at only 37 °C (99 °F), the normal body temperature of humans.

### At what pressure does blood boil?

At the nominal body temperature of 37 °C (98.6 °F), water has a vapour pressure of 6.3 kilopascals (47 mmHg); which is to say, at an ambient pressure of 6.3 kilopascals (47 mmHg), the boiling point of water is 37 °C (98.6 °F).

### What temp can kill you?

Mild or moderate states of fever (up to 105 °F [40.55 °C]) cause weakness or exhaustion but are not in themselves a serious threat to health. More serious fevers, in which body temperature rises to 108 °F (42.22 °C) or more, can result in convulsions and death.

### What outside temperature can kill you?

A body temperature of above 40°C is likely to be fatal due to the damage done to enzymes in critical biochemical pathways (e.g. respiratory enzymes). Most humans will suffer hyperthermia after 10 minutes in extremely humid, 60 °C (140°F) heat.

### How hot can the human body get before you die?

Hot. 44 °C (111.2 °F) or more – Almost certainly death will occur; however, people have been known to survive up to 46.5 °C (115.7 °F). 43 °C (109.4 °F) – Normally death, or there may be serious brain damage, continuous convulsions and shock.

0.858 atm

### Can air pressure kill you?

Compressed air that makes its way into a person through the skin can cause an embolism, and that can kill you if it reaches the heart, lungs or brain. Eye and ear injuries can occur easily around compressed air. 40 psi air can rupture an eardrum from 4 inches away and can even cause brain damage.

1083.8mb

### What is the highest fever a human can survive?

115 degrees Fahrenheit