So, I was reading about zeolites: https://en.wikipedia.org/wiki/Zeolite One of the things it is used for, is in the heating industry, namely: "Zeolites can be used as solar thermal collectors and for adsorption refrigeration. In these applications, their high heat of adsorptionand ability to hydrate and dehydrate while maintaining structural stability is exploited. This hygroscopic property coupled with an inherent exothermic (energy releasing) reaction when transitioning from a dehydrated to a hydrated form make natural zeolites useful in harvesting waste heat and solar heat energy. Zeolites are also used as a molecular sieve in cryosorption style vacuum pumps." The question is, how hot does the exothermic reaction get? how long the zeolites stay warm in room temperature?