Man of Honour
There are phase change systems (used to be called peltiers) that essentially electrically suck all the heat from one side and dump it out on the other, so when it is working right, the CPU side will be ice cold and the heatsink side will be roasting.
Don't get peltier cooling mixed up with phase change, they are quite different!
Peltier is what you're referring to, which are thermoelectric devices that can improve other methods of cooling by acting as a heat pump. Phase change systems on the other hand use a liquid/gas compressor/evaporator to get extremely low (negative 30c) temperatures!
