Before Reporting to the Judge
Prepare your dog for the trial day.
For instance, during club practice, you potty your dog, put gear on and walk directly onto the field.
During the trial, it might be 30 degrees Celsius (86 Fahrenheit). You potty your dog, and because of a large attendance, have to walk a while to the field.
Once you get to the field, you have to wait for your turn, or there might be a delay (the Judge needs a bathroom break). Meanwhile, your dog is waiting in a down position, getting hot and, potentially, tired.
Practice longer wait during club days to condition your dog.