Brief Answer:
needs workup to differenciate rigor from seizure

Detailed Answer:
Hello and Welcome

I appreciate your concern.

I have read your history carefully. The violent shivering episodes are not normal and require further work up before a final diagnosis is reached.

The initial investigations should focus on ruling out or confirming

a) Seizures / epilepsy
b) Rigors/ chills due to an infective cause eg Pneumonia
c) Panic attacks

In a seizure , after the episode, there is associated elevated temperature, tongue bite and /or urinary incontinence.

The raised temperature and abdominal pain which you complained of , can occur due to the violent shaking and muscle fatigue.

The investigations should include the following in consult with your doctor.

Full blood count, urea and electrolytes, Chest X ray.
erythrocyte sedimentation rate / C-reactive protein, and liver function tests
Blood cultures
Urine for microscopy and culture

If an infective cause is not found then an EEG can be done.
Blood sugar and electrolyte abnormalities should also be looked for to rule out any metabolic cause.

If the above investigations are normal I would suggest you to consult a psychiatrist so that a XXXXXXX mental state exam is performed to ascertain depression and or anxiety to rule out the possibility of a panic attack. A panic attack can very well present in the same way.

Hope this helps.
Let me know if you have any query

wishing you best of health

Thanks

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