Something odd happens when you expose the element gadolinium to a strong magnetic field: Its temperature jumps up. Remove the field and the temperature drops below the starting point. This behavior, known as the magnetocaloric effect, is usually found in ferromagnets, materials that lose their magnetism above a certain temperature. If it can be exploited it will prove very useful in refrigerators and air conditioners that no longer need motorized compressors and special refrigerants. Oak Ridge National Laboratory's Markus Eisenbach and colleagues are using ORNL's Jaguar supercomputer to push forward on a very important part of this puzzle. Using an application that took the 2009 Gordon Bell Prize as the world's most advanced scientific application, Eisenbach's team has been simulating the magnetic properties of promising materials, focusing in particular on the magnetocaloric effect. Its work is detailed in three recent papers in the Journal of Applied Physics.