Nice "find" Bill. The article gives an interesting, description of hypoxia. One that's very easy to understand. The examples they provided were very helpful.
 
Again nice introduction. Next stage of learning involes understanding of oxygen transport ( blood oxygen disassociation curves) as well as lung physiology (zones of West and other).
The above will help you understand blood oxygen saturation as well as thing like carbon monoxide poisoning as well as the effects of dehydration and colds.
Happy reading
 
Generally good article, but his definition of hyperventilation is totally wrong - it just means rapid breathing. There can be multiple causes, and the one he cites is one of the least likely.
 
There are very few things that CASA regulate that is better than the FAA, but the altitude for O2 here is 10,000. And I agree.

In fact even a long trip above 8000 I will use a bit of O2.

I ALWAYS use it at night regardless of the height if the flight is more than 20-30 minutes.