Ultratherm Heat pads

So I was at the Bean Farm's website looking around at their heat pads and started looking at the info sheet for the Ultratherm heat pads when a line caught my eye:
"You can place the heat pad inside or outside the cage."
Even with a thermostat connected to it my fear would be malfunctioning and overheating leading to burns or worse x.x
What do you all think? If you needed to would you use these inside your enclosures or would you be too paranoid of an accident?

NO I would not use the ultratherm in side. I would use a Kane pad (waterproof and generally superior to the rest) under certain circumstances but for me it would be a proportional thermostat as on/off types spike, with a second on/off as a back up fail safe system.