Why do i have problems when i swim in extreme hot/cold temperatures with sickle cell anemia?

Sickle cell anemia: Extremes of temperature and physical exertion tasks both the circulation of blood and the individual hemoglobin molecule. So when you are exercising in the heat or cold you are demanding more of the sickled red blood cell as well as your heart to deliver oxygen to your muscles and this is why it is problematic.

Blood flow changes: Swimming can cool the skin, even when it is warm outside. This can cause decreased blood flow, which has been shown to affect the sickling of sickle cells. If you continue to swim, it would be good to dry off quickly and put on a shirt quickly. This may help.