A pair of German designers have created the H-Agent, a tiny black box which absorbs heat from other sources (say, radiators, fires, or the cup of coffee you place on top of it), stores it using a phase change material (PCM), and then releases it later on when needed. However, rather than being something you carry around and place near a heat source, the H-Agent uses thermal sensors to find the hottest places itself. Inside the blank exterior is a Segway-like pair of wheels paired with heat sensors that allow the cube to go looking for the warmest place to gather energy. Later it releases this stored heat where it's needed — but exactly how and when isn't made clear.

The phase change heating material is nothing new — the same concept is behind the hand-warming pads that you activate by snapping a metal disc inside — but there's something charming about a tiny heat-loving robot that can keep you warm when need be. The idea won designers Andreas Meinhardt and Daniel Abendroth second prize in the International Design Competition of Prix Émile Hermès 2011, though they don't give any idea of how long it might be before the H-Agent makes it to your home.