This element maybe named HTCL would take heat and transfer it to cold. It could be used for bombs (with the new C-5) etc. It starts out at 0 degrees and for every 35.6 degrees that are on one side are added 1 degree is lost on the other side. I have no idea if its codeable and I'm sorry if this has been suggested before, I searched and couldn't find it.
@Ace I guess that would work too. It's just a matter of it being able to go to 9725 degrees at most with heat, and only -273 degrees at most with cold.