Ken, Tim just went and said the same things as I have I am not attacking you I just wonder how the animals would feel being kept at the same temps all the time with no where to retreat for the cooler temps. I can't say for sure that it is killing them, but again I ask how you would feel being put in a room at 90 or whatever and not having a cool side, I'll bet not very good. As for proof that animals use this in the wild I have been out playing and watching rattle snakes and I find the most in the morning warming up, but by the mid afternoon there aren't that many out they have gone under rocks and underground for the coolness of it and then in the evening when temps go down they come out and do their thing. This I have tonnes of proof of if that is what it takes. That is why our southern brothers have what is called night cruising. Again I'm not attacking you, but I question the heat thing.