Final answer:
Acclimatization is an important biological process enabling humans to adjust to high altitudes by increasing red blood cell count to compensate for lower oxygen availability, thereby preventing acute mountain sickness.
Step-by-step explanation:
The process known as acclimatization is the adjustment that the human body makes in response to chronic exposure to high altitudes, where there is a lower partial pressure of oxygen in the air compared to sea level. This lower pressure results in lower oxygen saturation levels in the hemoglobin in the blood, leading to a condition known as acute mountain sickness (AMS) when exposure is quick and without adequate adjustment time. Symptoms of AMS include headaches, disorientation, fatigue, nausea, and lightheadedness. However, over time, the body can adapt through acclimatization, prompting the kidneys to produce more of the hormone erythropoietin (EPO), which stimulates the production of more erythrocytes (red blood cells) to transport available oxygen more effectively. Consequently, people who live at high altitudes or who have acclimatized can engage in physical exertion without suffering from AMS symptoms.