All instruments
Hypoxia
Climb and see what thin air does to you and how long you stay clear-headed.
One breath
Saturationtypical, at rest
98%What you notice
By day you notice nothing
- Your blood takes up enough oxygen.
- At night your night vision already fades from about 5,000 ft.
- Air pressure
- 100% of sea level
- Oxygen in the air
- 21%, at every altitude
- Oxygen pressure in the air
- 159 mmHg (sea level 159)
- Time of useful consciousness
- no limit
Time of useful consciousness (TUC)
| Altitude | Typical, at rest |
|---|---|
| 18,000 ft | 20 to 30 minutes |
| 22,000 ft | 5 to 10 minutes |
| 25,000 ft | 3 to 5 minutes |
| 28,000 ft | 2.5 to 3 minutes |
| 30,000 ft | 1 to 2 minutes |
| 35,000 ft | 30 to 60 seconds |
| 40,000 ft | 15 to 20 seconds |
How long you can still act usefully without extra oxygen. Typical values: they vary per person and get shorter with exertion, smoking, fatigue and after a sudden loss of cabin pressure.
Test: find the squawk
Air traffic control gives you a transponder code. Find it as fast as you can, five times. The higher you take the test, the more codes there are, the more alike they look and the more your view blurs, most at the edge. A simulation: real hypoxia mostly goes unnoticed.