Hi..
Thanks for the query..
As per your explanation of symptoms that your son who is three years old is suffering from fever, cough, watery eyes and runny nose is pointing that he is suffering from upper
respiratory tract infection, also known as
Common Cold .
As it is a viral infection it 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:
1. Gargle with a warm saline solution that is by mixing 1 teaspoon salt in a glass of water and warm it to make a luke warm solution..
2. Take a combination of decongestant like
Phenylephrine,
mucolytic like Ambroxol and anti allergic levocetrizine and another combination of
Acetaminophen and Ibuprofen..
3. Do steam inhalations..
4. Avoid spicy and chilled foods..
5. Sip on warm water throughout the day..
6.Give him sufficient rest..
Hopefully the symptoms will resolve within a week and if it worsen consult a General Physician and get evaluated..
Hope this helps..
Thanks and regards.