Do not put the unit in a freezer to cool it down. This as bad as overheating it and both methods can push components outside their operating temperature and stop the console working permanently.
A successful shop owner in my group must plan the timing of when blasts are sent, because customers calling in to schedule swamps his service advisors, so they send the voice mail after the rush is over. He uses his voice and tells them quickly why he is calling. One example is he asks them to stop by to check their tire valve stems because there was a recall. I recommend you use something you feel passionate about that would be a good idea to blast.