Namaste Madbob
I think decompression sickness (the bends) comes from extended deep diving using compressed air.
CAAN regs require supplemental O2 above 10,000'
Acclimatisation does play a huge mega role. It is better to not use O2 whenever possible as it spoils acclimatisation. For landing below 19,000' & crossing passes I no longer use. However landing in the 'dead zone' the cannula O2 is always on above 20,000' for landings, prelonged ultra high altitude mapping, filming etc ('dead zone' - Mountaineers term for when above 20,000'+ as the body starts to seriously starve for O2 & vital body functions begin to shut down, on most people, but not all!)
Land Happy always
VF
