Body temperature tends to decrease because of a deficiency in thyroid hormone also. Many of the synthetic chemicals used to treat modern day home goods seem to impact this system. I'd be curious whether there is any correlation there.
That would be thymus, not thyroid. Those are pretty different glands.
The thymus is not the thyroid gland, if that's the connection you're trying to make. AFAIK the thyroid gland is not deliberately consumed unless as medicine.