What to do if infants and young children cough with phlegm. Coughing in infants and young children is relatively common, and is usually accompanied by symptoms such as phlegm or sore throat. Infants and young children have weaker body resistance, so they need to be careful in choosing treatment methods when treating coughs. Here are some effective cough treatments for infants and young children. Maintain indoor air circulation. When infants and young children cough, they need to maintain indoor air circulation to prevent accumulated air from aggravating the condition. You can open windows for ventilation or use an air purifier for air filtration. In addition, bathing the baby in the bathroom can relieve symptoms such as nasal congestion and coughing. Keep indoor temperature appropriate and do not allow infants and young children to pass