Judging by that answer I am going to assume (until you correct me) that you are using a rack system. That being said your entire arguement on temps based on the temps in Africa is a little irrivalent being that a plastic tub with some wood chips and a water bowl is nothing like their native habitat. There is no way you can create the temp fluctuations in a rack system that an entire area in the wild sees on a daily basis. There are tons of variables in the wild that are eliminated in an enclosure. You can't make bold statements regarding natural habitat then say I am only referring to specific things.