1. The process of putting heavy stress on relatively new electronic equipment. There are many superstitions as to why to do this, but the one that seems to be most agreed upon is if the piece of equipment or the system it is apart of have been relatively untested then "burning in" at maximum operating capacity for longer than should be asked of the system in normal usage will give and idea of expected performance capabilities and potential places that problems might occur. 2. The phenomenon of metal or other good temperature conductors melting into ice at a pace so rapid it seems like the object must have been burning hot when it was set down (even though the metal object was most likely close to the ambient temperature). It's makes often less thought of things like truss pins and R clips hard to retrieve once knocked out or set down unless they are retrieve almost immediately.