A Cooling Cell will accept as much heat as offered to it, so far as I know. However, it doesn't dissipate that heat, it stores it. If there is something adjacent to it which can actively draw heat from a component, it will do so.
Therefore, a Cooling Cell next to a quad uranium cell will absorb all the heat that quad cell produces. However, if there is a golden heat exchange component adjacent to the cooling cell, it will take that heat and distribute it among everything it is touching.
Ah, makes sense. Didn't think about the fact that the cooling cells will be 'cooled' too, since the exchangers try to evenly divide the heat. It makes sense now, thanks!