Hello, my question is why do i feel heat generating
The burning sensation that you describe it is termed paraesthesia. Since you are known to have diabetes, this paraesthesia could be an indication of diabetic neuropathy. I would suggest to visit a neurologist for neurological examination. Blood sugar status need to be reassessed. Similarly vitamin B12 levels, hemoglobin, vitamin D as well as thyroid hormones need to be checked.
I will recommend you to see a neurologist.
Hope this helps. Let me know if you need clarifications.