An altitude chamber, also known as a hypobaric chamber, is a device used to simulate the effects of high altitude on the human body, usually for purposes of research or training. Athletes, aviators and astronauts are typical examples of people who would use an altitude chamber. Higher elevation means lower oxygen levels and lower ambient air pressure. The effects of these changes on the human body can be quite severe, ranging from joint pain or headaches to seizures or even loss of consciousness. By simulating these conditions, an altitude chamber allows a person to become acclimated over time, and therefore less likely to succumb to the dangers of high altitude.
In research, an altitude chamber allows scientists to study the effects of hypoxia, or low oxygen, and hypobaric, or low pressure, conditions on the human body. Hypoxia occurs when the body's oxygen level is too low, resulting in symptoms such as nausea, dizziness, seizures or loss of consciousness. Hypobaric conditions — which can occur even in low altitudes when a low pressure front moves into an area — can result in joint or sinus pain and headaches. Symptoms of hypoxia and hypobaric conditions can vary greatly from person to person.
In training, an altitude chamber allows an athlete to acclimate his or her body to conditions which are difficult to replicate in everyday life. By using an altitude chamber to train, an athlete can slowly and safely adapt to performing under a variety of conditions. Altitude chambers use a vacuum pump to remove air out of the chamber at a constant rate, lowering the air pressure and simulating the conditions of high elevation. Inside and outside observers usually monitor the athlete or subject for safety.
In contrast, a hyperbaric or high pressure chamber can be used to aid someone suffering from the conditions of hypoxia or hypobaric conditions. A hyperbaric chamber raises the air pressure inside the container. This raises the oxygen level of the subject and simulating a decrease in elevation.
Altitude chambers are very expensive pieces of equipment and beyond the financial reach of most people. Some institutions make their altitude chambers available to the public by appointment, however. In addition, some portable devices allow altitude training by providing a mask for the subject that recycles exhaled oxygen, removing dangerous carbon dioxide and other chemicals, in order to lower the oxygen level and replicate conditions at high elevations.