There isn't a specific term for the falling of cold liquid. We usually describe it based on the context:

* Dripping: If the liquid falls in small drops.

* Pouring: If the liquid falls in a continuous stream.

* Spilling: If the liquid falls unintentionally.

* Raining: If the liquid is water falling from the sky.

You could also describe the liquid itself, like "falling cold water" or "falling cold milk".

Is there a specific situation or liquid you have in mind? That might help me give you a more fitting description.