Not to mention they are used for the heating of HUMANS, not snakes. Your core body temp is 98.6*. Ball pythons are meant to be kept at max 94*. If you need to heat up a human, the heating source must be higher than 98.6* which is much too high for a ball python.
It will burn the snake at some point. Those human heating pads get well past 115* which could even cook the snake.