Antidote
HBOT is done in a special tube or room that can handle high pressures (called a hyperbaric chamber).  100% pure oxygen is sent into the room for the patient to breathe.  However, the air pressure is increased to three times more than the normal air pressure.  This helps the lungs get more oxygen than they could if the patient were breathing at normal air pressure.  It also makes it easier for the blood to carry more oxygen to the entire body.