At which altitude does hypoxia symptoms begin to emerge?

Hypoxia symptoms typically begin to manifest around 10,000 feet. At this altitude, the partial pressure of oxygen decreases, which can result in decreased oxygen availability for the body. The onset of hypoxia can vary from person to person, but it's generally recognized that symptoms may start to appear once an individual ascends beyond this altitude without supplemental oxygen. Common symptoms include shortness of breath, reduced cognitive function, impaired coordination, and fatigue, which can escalate with higher altitudes if exposure is prolonged without the provision of oxygen. Understanding this threshold is crucial for pilots and aviators to effectively manage their exposure to higher altitudes and to take preventive measures, such as using supplemental oxygen when necessary.