That would be extremely hard to do where they live, being as, it's VERY rare to be over 75 degrees any time of the year. And in their dogs' case, it was 100% him rubbing his back on his dog house.
A dog rubbing the hair off his back won't have a scar. It will simply be missing hair. I've had 2 dogs with heat strokes, and it literally BURNS the back along the spine. It fries the skin, hair, all of it. We had to cut eschar, due to the full thickness burn, off the dog's spine with a scalpel to get to the actual flesh for it all to heal as it should. It took a long time for it to heal, and it took even longer for the hair to grow back as it should. Nu-stock never touched the scarring, and neither did anything else we used those years ago.