Related to the previous, and in the sure belief that Sol will not be able to provide an answer, here is a little bit on hydrated minerals at asteroids;
My bolding. From;
Hydrated Minerals on Asteroids: The Astronomical Record
Rivkin, A. S. et al (2002)
Now, I wonder what the measured temperatures were at the above mentioned comets? Well, not even 400 K, let alone 400 C!