Commond colds, sometimes called URI (Upper Respiratory Infection) are caused by viruses. With kids getting as many as eight colds per year or more, this contagious viral infection of the upper respiratory tract is the most common infectious disease in the United States and the No. 1 reason kids visit the doctor and stay home from school. Medicine can't cure the common cold, but it can be used to relieve such symptoms as muscle aches, headache, and fever. You can give your child acetaminophen or ibuprofen based on the package recommendations for age or weight.