I have edited my previous post above, because I went down and did a few tests on my RHP.
The Pro-Products RHP I have is significantly cooler than the CHL I used to use. RHP does get hot, but to get a serious burn a snake would have to be in contact with it for longer than just a few seconds. My ball has raised up to inspect it, but once he starts to feel the heat on his nose build up he backs away. Also, I'm able to rest the top of my hand against the pad continuously without feeling enough of a burning sensation requiring me to move my hand.
Also remember, your snake is not laying on the RHP, as it would with an UTH. When I hit the RHP with my temp gun, it measures at 143 degrees. If an UTH was being used and the temperature was measured in the tank at 143 degrees, I think you'd have some problems with burns if the snake remained on it constantly for the right amount of time. This is why they also recommend that a RHP be at least 6" away from any object placed underneath it, to prevent significant heat build-up.