What action should a person with sickle cell anemia take to prevent a sickling crisis?

In sickle cell anemia, hemoglobin S polymerizes when deoxygenated, causing red blood cells to assume the rigid sickle shape that obstructs small vessels and triggers a vaso-occlusive crisis. Cold temperatures cause vasoconstriction, which slows blood flow, promotes deoxygenation, and dramatically increases the risk of sickling. Avoiding extremely cold temperatures is therefore a well-established preventive strategy for patients with sickle cell disease. Increasing daily oral iron consumption is incorrect and potentially harmful; iron supplementation is not indicated for sickle cell anemia, and iron overload is actually a complication seen in patients who receive frequent transfusions. Taking pain medications as prescribed is important for managing an active crisis but does not prevent the sickling process from occurring in the first place. Performing strenuous exercise every day is contraindicated because vigorous exercise leads to increased oxygen consumption, tissue hypoxia, lactic acid production, and dehydration, all of which promote sickling. Other preventive measures not listed here include staying well-hydrated, avoiding high altitudes, managing infections promptly, and avoiding emotional or physical stress. The keyed answer is confirmed as correct.