My Daughter Was At Softball Practice Is 98 Degree Heat

My daughter was at softball practice is 98 degree heat tonight and starting having sharp stomach pains. She went to the bathroom once and he bowels were solid. After returning to practice, she had to use the bathroom again and this time had a large and loose bowel movement.
She is now at home in air conditioning and feeling much better.

I am trying to determine if it's a stomach bug or if the heat triggered something in her?