Have you listened to the Dr.Stan/Dr. Fleschas interview yet? In that interview he talks about a woman who lost her ability to sweat, a couple of years later she died of breast cancer....
When we sweat, we sweat iodine(if we've got any:), in fact there have been studies that show that heavily sweating athletes become iodine-deficient very easily.
And I noticed this summer that I sweat beautifully, very evenly.