I think you guys need to rethink how your body cools down.
for best cooling performance for rear passengers, aim the center louvers from the dashboard grilles slightly upwards. This shoots air across and as its cold air it will naturally fall because its heavier. It will fall on the passengers.
The other best practice is to aim some air at your feet.
Once comfortable - turn down the blower to a comfortable temperature.
Also make sure the passenger cabin is not letting hot air from the door cards into the interior.