Which of the following could be a symptom of hypoxia in flight?

Hypoxia occurs when there is an inadequate supply of oxygen to the body, particularly in high-altitude situations, such as in flight. Each symptom listed can be associated with hypoxia.

Feeling vaguely unwell is a common initial symptom of hypoxia. As the brain receives less oxygen, general malaise or a sense of discomfort can manifest. This is often one of the early indicators that a pilot or passenger might experience when exposed to low oxygen environments.

Hot flushes can also occur, influenced by the body's reaction to decreased oxygen levels. As the body adapts to hypoxia, it might try to compensate in various ways, leading to sensations of warmth or flushing.

Impaired night vision is a significant concern with hypoxia, as reduced oxygen supply impacts the function of the retina and other visual pathways. Night vision relies heavily on adequate oxygenation, and it's well documented that hypoxia can lead to difficulties in seeing in low-light conditions.

Hence, all these symptoms can be linked to hypoxia, making the conclusion that they collectively represent potential symptoms of hypoxia when flying accurate. Recognizing these symptoms can be crucial for flight safety and ensuring that the necessary steps are taken to counteract the effects of reduced oxygen levels.