I am a new iguana owner. I am so worried that the NJ cooler-than-usual summer
temps are unhealthy.

I have her enclosure on a card table and have rolled an oil-filled radiator
under the table. While this does release heat into the room, it also warms the
table and bottom of the enclosure. This appliance is on low and has a buffer
between the tank bottom and I am not worried about the heat rock effect.

I also have heating pads - in the plural - that will do the same thing.

I am writing to find out:
#1 does anyone have an opinion on which method is more efficient?
#2 has anyone ever heard of radiant substrate heat?