Hi,
My suggestion would be to do a search for the phrase "heat rock" pick the best threads explaining how dangerous hey are then make your dad read them.
$10-$20 for flexwatt from rich at repltile basics plus $70-120 for a very reliable thermostat is a heck of a lot less expensive than a course of vetinary treatment to cure an injured animal or replace a dead one.
The main thing to watch out for withn the heatrock is that it can deleop hot spots on its surface hot enough to burn your new pet.
dr del