Final answer:
Sleeping in a well-ventilated room would not cause sickling of red blood cells in someone with sickle-cell anemia, contrary to stressors like vigorous exercise, travel at high altitude, or malaria which can result in significant complications due to lower oxygen levels or infection.
Step-by-step explanation:
The cause of sickling in red blood cells in someone with sickle-cell anemia commonly includes various stressors such as low oxygen levels, dehydration, infection, and sometimes physical exertion. When a person with sickle-cell anemia is exposed to these stressors, the hemoglobin S within the red blood cells can cause them to become crescent-shaped, leading to a variety of health issues. However, sleeping in a well-ventilated room is not a potential cause of sickling because it generally provides ample oxygen, which can help prevent the sickling of red blood cells. On the other hand, vigorous exercise, travel at high altitude, where oxygen levels are low, and malaria, which can induce hypoxia, could potentially cause or exacerbate sickling in individuals with sickle-cell anemia.