Complex sentence: It is the period of time from the interruption of the oxygen supply or exposure to an oxygen-poor environment to the time when useful function is lost, and the individual is no longer capable of taking proper corrective and protective action.
Split into simpler sentences: It is the period of time from the interruption of the oxygen supply or exposure to an oxygen-poor environment to the time when useful function is lost. The individual is no longer capable of taking proper corrective and protective action.