Permanent kidney damage that is due to overheating in hot weather. Is it a matter of impurities building up in the kidneys and urinary tract due to dehydration or is there more to it than that?

Heat illness and hyperthermia can cause a number of injuries to the kidney including dehydration, low blood flow injury due to low blood pressure, high blood potassium, accumulation of acid in the body and clogging the kidneys with muscle proteins (myoglobin) that can be produced in excess during heat illness. As body temperature increase, a number of bad things happen to circulation and body metabolism that can lead to kidney injury.