Sarah was cooling off too quickly after exercising hard.  She started doing what?\nOptions:\n- relaxation\n- sweating\n- shivering\n- palpitate\n- chills
A step-by-step solution is:
shivering
Shivering is the act of shaking uncontrollably.

Muscles generally shake uncontrollably after getting fatigued.

Exercise causes muscles to get fatigued.

.

Therefore, the answer is shivering