Heat stroke can cause damage on the body by unconsciousness and fever (fevers can cause damage/infections on the brain). Heat stroke is from failure of the body's heat management system (e.g.: not sweating enough or no sweat at all).
Answer:
Cooling down allows your body temperature, blood pressure, and heart rate to return to their normal levels. Stretching your muscles while they're still warm can help to reduce lactic acid buildup, reducing your chance of muscle cramps and stiffness.
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