Help me please! what's wrong and how to stop it when/if it comes again?

during dance for no reason, i started feeling nauseous and my legs started getting shaky and weak. after dance i drank some water and all of it went away. so they night went on yada yada yada then i fell asleep around 10. i woe up about 11:30 and i was sweating . it was hot in the house, well not really it just felt like it to me. i cooled down by 12:00 and i was feeling better. i didn't throw up, or anything and my stomach wasn't hurting. do any of you know what was wrong? i feel fine now , but still.