If the student is suffering from water intoxication, then his blood is diluted. Based on the situation, the patient's blood is hypotonic. The doctor most likely administered hypertonic IV to restore the tonicity of the blood back to normal. The water will flow to where the salt is. If a hypertonic solution (high salt solution) is introduced into the body, the salt will help dehydrate some of the water and improve the patient's water levels.