Hi sjo1208.
With the details you posted, you're light years away from an MS diagnosis.
Surely damaged nerves may respond differently under heat, however, since the underlying cause has not been established, we can only speculate that it is some kind of paresthesia.
Make sure you rule out the following:
Hypocalcemia, hypothyroidism, deficiencies in Vitamin B5, B12 (methylocobalamin B12), vitamin D and tissue levels magnesium.
Best wishes,
Niko