At the higher altitudes, the TUC becomes very short; considering this danger, the emphasis is on prevention rather than cure.
For orbital altitudes and above, that is, direct exposure to space, 6–8 seconds of consciousness is expected.
Generally, old age tends to reduce the efficiency of the pulmonary system, and can cause the onset of hypoxia symptoms sooner.
This can be useful for identifying individual symptoms of hypoxia, along with rough estimates of the altitude that causes problems for each person.
Identifying symptoms is often helpful for self-diagnosis in order to realize when altitude should be reduced.