---
title: "Could you survive — conditions"
description: "16 questions about surviving conditions, each with what happens physiologically and in what order."
url: https://atoneplace.net/could-you-survive/exposure/
site: "At One Place"
---

# Conditions

16 questions in the conditions category.

| Question | Answer |
| --- | --- |
| 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. |
| How long can you survive if an aircraft cabin decompresses? | Roughly 30 to 60 seconds of useful consciousness at 35,000 feet — which is why the mask goes on before helping anyone else. |
| How much carbon dioxide can you breathe before it kills you? | Above about 5 per cent you get breathless within minutes; above 10 per cent, unconsciousness follows quickly. |

- [Can you survive being struck by lightning?](https://atoneplace.net/could-you-survive/lightning-strike/) — 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?](https://atoneplace.net/could-you-survive/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?](https://atoneplace.net/could-you-survive/vacuum/) — You do not explode. Consciousness goes in about fifteen seconds from oxygen leaving the blood.
- [How long can you survive in extreme heat?](https://atoneplace.net/could-you-survive/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?](https://atoneplace.net/could-you-survive/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?](https://atoneplace.net/could-you-survive/radiation/) — 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?](https://atoneplace.net/could-you-survive/carbon-monoxide/) — 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?](https://atoneplace.net/could-you-survive/fire-smoke/) — 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?](https://atoneplace.net/could-you-survive/extreme-noise/) — 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?](https://atoneplace.net/could-you-survive/high-pressure-depth/) — 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?](https://atoneplace.net/could-you-survive/g-force/) — 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?](https://atoneplace.net/could-you-survive/electric-shock/) — Current decides it, not voltage — around 100 milliamps through the chest can stop the heart.
- [How long can you survive in boiling water?](https://atoneplace.net/could-you-survive/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?](https://atoneplace.net/could-you-survive/high-altitude/) — Indefinitely up to about 5,500 metres if you acclimatise. Above 8,000 metres the body only deteriorates.
- [How long can you survive if an aircraft cabin decompresses?](https://atoneplace.net/could-you-survive/cabin-decompression/) — Roughly 30 to 60 seconds of useful consciousness at 35,000 feet — which is why the mask goes on before helping anyone else.
- [How much carbon dioxide can you breathe before it kills you?](https://atoneplace.net/could-you-survive/high-co2/) — Above about 5 per cent you get breathless within minutes; above 10 per cent, unconsciousness follows quickly.