Further still, at 150 feet, you enter a dream state caused by the high levels of carbon dioxide and nitrogen gas in your bloodstream: for a moment, you can forget where you are and why. At 300 feet, the pressure is so extreme that your lungs shrink to the size of oranges and your heart beats at less than half its normal rate to conserve oxygen. You lose some motor control. Most of the blood in your arms and legs has flooded to your body’s core as the vessels in your extremities constrict. Vessels in your lungs swell to several times their normal size so they won’t be crushed by the incredible pressure.
Then comes the really hard part. You open your eyes, struggle to force your semiparalyzed hand to grab a ticket from the plate, and head back up.