oxygen

my dad is already taking oxygen he has it set at 5, he is now very sick and has added his portable oxygen tank.  So he is now wearing both oxygen tubes to have a total of 10, Is this even healthy?  Can this do any damage?  If he stays with the 1 oxygen when we check his oxygen level is bout 70 but with both going he stays around 94

[National Jewish Health]

Your dad should be seen by a doctor, without delay.  Taking too much oxygen can be harmful.  It could result in a build-up of carbon dioxide in his body and that can be quite dangerous.  From your description, he would appear to be at high risk for hospitalization.