If a 4.5-month-old child has a cold or a runny nose, the following measures can be taken: 1. If the symptoms of a cold or a runny nose are relatively mild, you can relieve the symptoms by drinking more water and combining with a nasal massage, or you can use a warm towel to apply a hot compress to the child’s nose, which will promote blood circulation in the nasal cavity, reduce the phenomenon of swelling in the nasal cavity, and alleviate the symptoms of a runny nose. 2. If the child’s symptoms of a cold or a runny nose are relatively serious, you can take cold medication to treat them. If the symptoms of cold and runny nose are more serious, you can take cold and flu medication, clinically more commonly used are pediatric aminophenol xuanamin granules, you can also take rhinitis granules and other proprietary medicines, can eliminate nasal inflammation, relieve the symptoms of cold and runny nose. If the child has fever in addition to the symptoms of cold and runny nose, parents are advised to take the child to the doctor for treatment.