A 2-year-old boy (Weight: 11 kg; Length: 81 cm) was brought to the doctor for recent onset of fever. A runny nose and a nonproductive cough that lasted for 2 days accompanied the fever. The child was apparently well prior to fever onset. The patient was treated with paracetamol and the fever subsided for 5-6 hours, during which time the child became active. The next day the patient was brought back to the same doctor because the fever had returned and the child was irritable. On initial physical examination, his temperature was 102 degreesoF, pulse was 120/min, and the respiratory rate was 30 per min. Coryza was positive and accompanied by both nasal and throat congestion. Examination of ears, chest, and other systems were normal. The child coughed especially when lying down. The patient’s medical history showed that he had recent contact with an elder sister who had a fever and cold; however, no past history of similar disease was noted.