Hi.. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concerns.. As per your complain it seems that the symptoms of low grade fever along with coughing and choking with phlegm and vomiting can be due to severe upper respiratory tract infection, influenza of flu,lung infection etc.. I would suggest you to consult an Otolaryngologist or Paediatrician and get evaluated and a thorough clinical evaluation and investigations like throat swab culture, sputum culture, blood test etc can be done to rule out the exact cause of the problem and can be treated accordingly.. In case it seems like viral infection, you need not to take antibiotics.. He can be advised to take Tylenol for fever, decongestants like Pseudoephadrine, mucolytics like ambroxol, anti allergics like Benadryl.. Saline nasal drops can help in reducing congestion.. Do stem inhalation and use a humidifier in his room.. Give him plenty of warm fluids.. Avoid chilled and spicy foods.. Give him ample of rest and semisolid diet.. Do warm compresses over his chest.. Hope this information helps.. Thanks and regards. Dr.Honey Nandwani Arora.