Hi.. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concerns.. As per your complain it seems that your son is are suffering from upper respiratory tract infection leading to green mucous formation and also congestion along with fever.. The infection will however resolve once the virus will complete its cycle in human body.. As of now you can start with supportive treatment to relieve the symptoms like Gargle with a warm saline solution, doing steam inhalation and use a humidifier in his room.. Give him tylenol to reduce fever.. Put saline nasal sprays as it loosen mucous and ease in drainage and relieves congestion.. Give him warm fluids to drink.. Avoid cold and spicy foods. You can also give antihistamines like Benadryl.. In case if it does not resolve consult his treating surgeon and get him evaluated.. Hope this information helps.. Thanks and regards. Dr.Honey Nandwani Arora.