Thyroid and temperature?

I was diagnosed with underactive thyroid but since have gone the other direction to overactive thyroid. I then got this real nasty cold and my temperature has been up to 99.7. For three days going on four days, I have had a low fever. I wasn't sure if it's related to my cold or the thyroid problem. It won't seem to go away and is making me have the chills. Anyone have any advice or experience in this manner? Thanks