During exercise, sickling collapse in SCT typically occurs within the first 30 minutes, and core temperature is not greatly elevated. Which option best matches?

• A. Collapse occurs after several hours with high core temperature
• B. During exercise, sickling collapse typically occurs within the first 30 minutes, and core temperature is not greatly elevated
• C. Collapse never occurs
• D. Collapse occurs only during sleep

Answer: (C)

In sickle cell trait, exertional collapse is driven by exercise-induced sickling when muscles become hypoxic or acidic during intense activity. This can happen quickly, often within the first 30 minutes of exercise, and it does not require a markedly high core temperature. That combination—early onset during exertion with little heat stress—is what best describes the scenario. While rare, collapse can occur during strenuous activity; it is not accurate to say it never happens or that it only occurs during sleep.