Brief Answer:
Needs work up and management accordingly

Detailed Answer:
Thank you for asking

I read your question and i understand your concern. History of rigors and chills with out fever and few episodes of diarrhea, congestion symptoms and not responding to supportive conventional therapies of decongestants and anti pyretics, should be evaluated.

Take your grandson to a doctor, if he is 14 then he needs an internist , they will run some baseline work up, do some radiographs of chest and sinuses, urine exam, stool exam and will try to find the focus of infection. Treatment will be directed accordingly. No matter what it is , it is easily treatable and some rest with supportive care would be advised.

I hope it helps. Take good care of your grandson and yourself and dont forget to close the discussion please.

Regards
Khan

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