A nurse in the emergency department is caring for a client who collapsed after playing football on a hot day. After reviewing the admission laboratory findings (Sodium 152 mEq/L, Potassium 3.6 mEq/L, Chloride 105 mEq/L, Glucose 102 mg/dL, BUN 18 mg/dL, and Creatinine 0.7 mg/dL), the nurse recognizes that these findings are consistent with which of the following conditions?