Okay this might sound a bit convoluted, but this may be related. If your MSM does not contain any molybdenum, you may be causing some thyroid issues by increasing your susceptibility to candida toxins.

Let me explain. MSM requires moly to be used in many of the body's processes. Candida toxins also demand moly to be broken down in the body. When these toxins go unmetabolized, they help to increase candida. Candida can interfere with estrogen elimination in the body(male or female) and that imbalance can affect the thyroid which also affects temperature regulation in the body.

5g of MSM likely requires much more moly than you are getting in your diet. And if you had a diet low in moly or candida before this change in supplementation, in other words, if you were already moly deficient, your reaction to the MSM would be quick and intense. For me it was aggravated IC and kidney pain.

Another possibility is the affect that sulfur(MSM) has on copper. Copper facilitates iron in several energy production activities in the body. MSM reduces stored copper, good for some, bad for others. Less copper to work with, means impaired iron use. Many cases of iron deficiency are actually copper deficiencies.

Good luck.