Salt from Dallol, Ethiopia

Origin
Dallol, Ethiopia currently holds the record for the highest recorded average temperature for an inhabited location. It is a location well known for its abundant salt mines, where salt is not only traded and shipped, but also used, in blocks, to form buildings.

Effects
This salt is always active. Depending on how much salt is kept together, it will drastically increase the temperature of the surrounding area.

Storage
For safety and to prevent the activation of nearby artifacts, the salt is separated into several manageable piles, kept in hermetically sealed, nitrogen-cooled boxes, each kept a minimal but safe distance from each other.