How long can you survive if an aircraft cabin decompresses?

Airliners cruise at 10,000-12,000 metres where the outside pressure is roughly a quarter of sea level, and the cabin is pressurised to the equivalent of about 2,400 metres. A rapid loss of that pressure gives a window called the time of useful consciousness, which is not the time to death but the time during which a person can still perform a purposeful action. At 35,000 feet that window is around 30 to 60 seconds, and it shortens sharply with altitude: about 15 to 20 seconds at 40,000 feet. Hypoxia is insidious rather than dramatic, producing euphoria and confident incompetence rather than a sense of suffocation, which is exactly why the safety briefing insists on fitting your own mask first. The aircraft response is an emergency descent to below 10,000 feet, typically completed in a few minutes, after which supplemental oxygen is no longer needed.

What happens, in order

Times of useful consciousness compiled from published aviation physiology tables; individual variation and rate of decompression both matter.

Physiology, not instruction. Every figure here is a population range under particular conditions, and individual variation is large — temperature, exertion, fitness and health move all of them substantially. Nothing on this page is medical advice.

Conditions

• Can you survive being struck by lightning? Usually, yes — around nine in ten people struck by lightning survive, though many are left with lasting injuries.
• How long can you survive in freezing water? Around an hour before unconsciousness in water near 0 °C — but the first minute is the one that kills most people.
• What happens to your body in a vacuum? You do not explode. Consciousness goes in about fifteen seconds from oxygen leaving the blood.
• How long can you survive in extreme heat? It depends on humidity more than temperature — once the wet-bulb temperature reaches about 35 °C, sweating cannot cool you at all.
• How long can you survive in extreme cold? Hours in still air with dry clothing; under an hour in wind at -30 °C — and people have survived core temperatures near 12 °C.
• How much radiation can a human survive? Below about 1 sievert most people recover; around 4.5 sieverts kills roughly half; above 8 sieverts survival is very rare.
• How long can you survive carbon monoxide exposure? Hours at low concentrations, minutes at high ones — and it has no smell, colour or taste to warn you.
• How long can you survive in a house fire? Around three minutes in a modern room before flashover, and smoke rather than flame is what kills most people.
• How loud does a sound have to be to kill you? Sound alone cannot exceed about 194 dB in air — beyond that it is a blast wave, and blast is what causes injury.
• How deep can a human go before pressure kills them? About 200 metres on a single breath, around 60-70 metres on air, and roughly 500-700 metres in a saturation chamber.
• How much g-force can a human survive? About 4-6 g sustained before blacking out, 9 g in a pressure suit, and over 100 g briefly in a crash.
• How much electricity can a human survive? Current decides it, not voltage — around 100 milliamps through the chest can stop the heart.
• How long can you survive in boiling water? No meaningful time. Water at 100 °C causes full-thickness burns instantly, and burns over a large area are fatal.
• How long can you survive at high altitude? Indefinitely up to about 5,500 metres if you acclimatise. Above 8,000 metres the body only deteriorates.