Brief Answer:
likely cold intolerance or a uti

Detailed Answer:
Thank you for asking

I read your question and I understand your concern. Shivering has many reasons. Old age with hypothyroidism is likely the cause of this shivering due to cols intolerance. Other possibilities are of an infection of a urinary tract. Keep her warm and get a fresh thyroid hormones assays as well as as routine urine exam. Management will be planned accordingly.

I hope it helps. Consult your doctor as our advice is just for education purposes only.

Take care
Khan

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