Would mixing up the trans cooler lines cause it not to cool properly?

I was wondering on a tranmission cooler does it matter the way you connect the lines on the top and bottom of the cooler? If mixing up the 2 lines will this cause the trans fluid not to cool properly?

Hi,

No, But I have always hooked it up to pressure up on
Engine Oil and tranny coolers mounted vertically.

Later :)

jaykar