Sure betas like temperatures of 75*+, but they are the one fish that I am willing to slide on. They can live fine in unheated water, and I would rather get one and put it in cool water (like it is already in at the LFS) and give it a lot of space to swim around in. If we dont do it, someone else will and 9/10 times house the beta in half a gallon or less with no heat. FishRmylife lives in Cali, and right now I am having trouble cooling my water down! Besides that, preciousgems you are totally right about the high amonia levels in a gold fish tank so that might stress out a beta.
FishRmylife, sorry about your beta. You have scared me about your cave, my cat fish lives in one of those caves that I made for him, I would be so sad if he got hurt, but it seems sturdy to me. What fish would you want to put a beta with?