I don't have a problem just curious.

If one has a submersible pump. I was reading in another post, which I can't find that if the pump was pulling water from on top of the pump it will overheat unless there is a shroud or was enough flow past the pump. I think the figure was 2 gpm.

My question is if the water in the well is 68* and the pump is running, why would it make a difference which direction the water was flowing? I would think there would be enough flow to cool the pump no matter what as long as it didn't run dry.
Would the pump build up enough heat to actually warm the column of water above the pump? Wouldn't the dissipation of heated water next to the motor, being cooled by the surrounding water pulled into the pump, be cool enough? How hot do the pumps get and how hot can they stand? I would further imagine the heated water would rise bring cooler water into play.
Any thoughts?