If it was a temperature problem you should have see a temperature warning. I had a fan wire break and did get a warning.What was the air temperature? You can probably assume the ground temperature while it sat there waiting to launch would be much hotter than the ambient air in a desert setting. According to DJI, operating temp range of a Phantom 4 Pro is 32° to 104°F (0° to 40°C). I'm sure under certain conditions a desert floor could reach 120F+ in the sun. That may have been a factor that the electronics just couldn't handle, especially the batteries. But just a guess. You did mention cooling it off a bit before flying on previous missions that were successful. However, I don't know what the typical desert temps are at this time of year there.