A pilot experiencing the effects of hyperventilation should be able to restore the proper carbon dioxide level in the body by

Explanation

Hyperventilation is an excessive loss of carbon dioxide caused by breathing too fast or too deeply. PHAK Ch. 17 lists the cure as slowing the breathing rate, breathing into a paper bag, or talking aloud, and AIM 8-1-3 likewise says symptoms subside once breathing is brought back under control and that breathing into a paper bag speeds the rebuilding of CO2. Breathing more deeply or faster would make the CO2 deficit worse.