All I have to say is that I like to keep my animals outside here in Florida. do a little research on what our conditions have been here in Bushnell Florida for the last six months, or even the last week and you will be an idea of what these geckos can and do tolerate very well.
It is very rewarding to go outside on an exceptionally warm day and see the coloration that my henkeli, fimbriatus, sikorae sikorae, and pietchmanni are showing. On the same note, when was the last time most of you had a chance to see what your animals look like at 50 degrees (F) or lower? After a lengthy summer thunderstorm? In the middle of summer when it is in excess of 90 (F) in the sun but through strategic placing of full mesh cages and spraying, the animals fare just fine.
Im fortunate to live in the far south, and I cant quite dial in conditions like those of you with climate controlled rooms, misting sytems and helix controlled racks, but I get a certain type of satisfaction from letting nature do most of the work.
Try and utilize what ever facets of the natural approach that you can take from my advise, using the sun for a few hours per week may make a big difference, having small screen cages that may be used to expose animals to rainstorms, and perhaps even putting breeders outside and allowing them to get colder than what our over-standardized husbandry literature has yet acknowledged.