Which of the following is NOT classified as an altitude illness?

Heat stroke is not classified as an altitude illness because it occurs due to excessive heat exposure and dehydration, rather than changes in altitude. It presents as a critical condition resulting from the body's inability to regulate its temperature, typically due to prolonged physical exertion in hot environments or insufficient fluid intake.

In contrast, altitude illnesses specifically arise as the body struggles to adapt to lower oxygen levels and decreased atmospheric pressure at high altitudes. Acute mountain sickness occurs due to a rapid ascent to high altitude without adequate acclimatization, leading to symptoms like headaches and nausea. Pulmonary edema is another serious condition that can develop when fluid accumulates in the lungs, a result of the body’s response to high altitudes. Sickle cell trait reaction can occur in individuals with this genetic condition when exposed to high altitudes, potentially precipitating painful crises due to lower oxygen levels.

Thus, heat stroke is unrelated to altitude changes and is classified under environmental heat illnesses, distinguishing it from the recognized altitude illnesses.