At what altitude does the Space Equivalent Zone occur?

The Space Equivalent Zone is recognized as occurring above an altitude of 50,000 feet Mean Sea Level (MSL). At this altitude, the atmospheric pressure is significantly reduced, leading to a decrease in oxygen availability, which can result in hypoxia if supplemental oxygen is not used. This altitude also presents unique physiological challenges that affect the human body, requiring specific equipment and training for those who operate within this region. The conditions here simulate aspects of space flight, where life support systems, including oxygen delivery, become critical due to the extreme environment. Understanding this altitude is crucial for flight medics and others in the aviation and aerospace fields, as it determines the level of risk and the necessary precautions to ensure the safety and well-being of individuals operating in these high-altitude situations.