Thanks to a recently discovered effect in magnetic tunnel structures, thermoelectric voltages in nano-electronic junctions can be controlled. The heat which occurs in tiny computer processors might soon be no longer useless or even a problem. On the contrary: It could be used to switch these processors more easily or to store data more efficiently! These are two of the several potential applications made possible by a discovery made at the Physikalisch-Technische Bundesanstalt (PTB).