Probably underdosing of medicine. Give 10-15 mg/kg of paracetamol,repeat every 4 hours if required. If mild,just give steam inhalations for cold and cough and decongestant nasal drops for nasal block or increased cough on lying down. If not improving OR accompanied by other symptoms like wheezing or breathlessness or dullness and refusal to feed,consult your paediatrician.