Death by ... Water?

Michelle was a healthy 25-year-old running in her fi rst marathon. The hot and humid weather had made all the runners sweat profusely, so Michelle made sure she drank water at every opportunity. Gradually, she began to feel weak and confused. At the end of the marathon, Michelle staggered into a medical tent. Complaining of headache and nausea, she collapsed onto the floor. Volunteers quickly gave Michelle water for dehydration. Soon, her condition worsened and Michelle was rushed to the hospital, where she was gripped by a seizure and went into a coma. Why did treating Michelle with water make her condition worse? As you read this chapter, look for clues to help you predict how water made Michelle sick. Then, solve the mystery.