I did some intense exercise walking up a mountain and I had some type of attack where my eyes rolled behind my head, eyes were blurry, felt cool, felt like I couldn't stand, and tired and thirsty and now after that my foot hurts and isn't as strong in movement. Why is this happening?I did some intense exercise walking up a mountain and I had some type of attack where my eyes rolled behind my head, eyes were blurry, felt cool, felt like I couldn't stand, and tired and thirsty and now after that my foot hurts and isn't as strong in movement. Why is this happening?