Where the hell do you read such shyte???A mask can improve a person's intake of oxygen by increasing the amount of CO2 they breath in.
Google for hyperventilation and how to treat it. Hypoxia can be the result of too little ( yes too little ) CO2 in the air. One treatment is re-breathing air using a paper bag for upto 15 breathes to increase the amount of CO2 being breathed in and thus restore the gas balance in the lungs.