could you use a small space heater to heat a large enclosure to about 85 and then use lights to make the basking area 95??? Since good sized iguana enclosure are basically the size of a small room. Of course the heater would have to be a good one with room size setting, temperature control, cool touch housing, and all that stuff. and it would have to be in something so the iguana couldnt come in contact with it.
This of course is just an idea. Please don't yell at me. 


