Absent a change in the laws of physics, it seems to me that inserts for pockets and other change-carrying containers that keep the temperature cool (but not cold, as that causes bloom on chocolate) would be ideal. We don't want to mess with the melting point of chocolate, as that's part of the fun of eating the stuff!
Hm... maybe the foil coating could be a perfect thermal insulator? Then the chocolate would remain at its temperature when inserted into the foil until opened.
