i use heat tape (flexwatt) as long as it is regulated by a thermostat you should not have any problems. i know ap cages have heat rope in their cages/racks and alot of people use them. i also know alot of people use radiant heat panel in their arboreal setups with no problems.
so how do u attach flexwatt to an AP cage? do u just stick it on the bottom? if so is it possible to put the cage on furniture or a stand and not burn it?