FAL and BeCool both sell tranny coolers (stacked-plate as well as fin-and-tube) with fans if you are serious about cooling your tranny. Looking at a particular FAL unit (with thermostat) for my DD pickup to help with hauling horses. Draws 8.5 amps; which is minimal, considering the benefits.
I've never been to Richardson - I think. Most of my last trip through Texas was made West-to East along I-10; and it was dark from New Mexico 'til somewhere outside of San Antonio.
Regardless, I'm pretty sure you couldn't be much worse heat-wise than Yuma in the last couple of weeks. From what I've heard, the 4R70W tranny in my pickup doesn't really like the operating temperatures to which I subject my personal example - at least not this time of the year.