What is a correct list of hypoxia symptoms?

The recognition of hypoxia symptoms is crucial for pilots, as the oxygen deficiency can significantly impair cognitive and physical performance. The correct option highlights key symptoms often associated with lower oxygen availability at high altitudes.

Euphoria can occur as brain function is affected by reduced oxygen, leading to impaired judgment and an overall sense of well-being despite danger. Increased heart rate is another critical sign, as the body attempts to compensate for the lack of oxygen by pumping more blood. Loss of touch may indicate neurological effects on sensation and proprioception, while cyanosis—a bluish discoloration of the skin—serves as an outward indicator of inadequate oxygenation in the blood. Lastly, somnolence, or excessive sleepiness, can occur due to insufficient oxygen reaching the brain, leading to a state where a person may struggle to stay alert or awake.

Understanding these symptoms helps pilots recognize hypoxia and take timely corrective actions, such as descending to a lower altitude or using supplemental oxygen, thereby ensuring safety during flight operations.