Yes, using a battery box from Wal Mart I measured about an 8 degree F temperature rise on the box exterior after running for 10 hours (box closed with lid).
Test setup included a closed battery box containing a hub and 600 watt Corsair power supply (no additional fan), five SSCs of 100 nodes each, and one SSC with 50 nodes for a total of 550 nodes. All SSCs were loaded/run with the test software to exercise the nodes fully and run simultaneously for the 10 hours. I used a non-contact IR thermometer to run the test; I checked several objects in the room to make sure the thermometer was accurately reading test targets.
I considered instrumenting the inside of the box to measure temps at the PS and on the hub, but with such a small temp rise on case exterior I do not consider this necessary. By the way, I left a number of the nodes bundled as received from Ray, and the node temps rose to 115F in this test setup. Obviously, spreading them out and using a more typical duty cycle for a show will result in substantially lower temps.
All in all, it looks like there's nothing to worry about with the Battery Box setup from a temperature standpoint.