Something inexpensive to keep you occupied, not sensitive to heat.
I can't think of any animal that isn't sensitive to heat in one form or another.  I don't think goats, even small ones, are free of that.  
If you're doing well with chickens, how about some other breeds of chicken?  How about turkeys?  Guinea hens?  Ducks?
A friend of mine was suffering from empty nest, and got herself a beautiful purebred cat.  It's a house cat - she spends a lot of time grooming it and really enjoys it.  I think it's a British Shorthair - she sent me pics a long time ago.  It's a gorgeous greyish-blue color with creamy colored patches.  It looks like a painting, LOL.  Incredible.  And because the color of the eyes isn't right for the show requirements, she didn't pay the usual price for the cat, either.  All around it worked out very well.  She said the cat is so affectionate and is always ready to be petted.
I've known a few other people who have taken older neutered show cats for free.  They can make wonderful companions.  They get a lot of handling and training so are very nice to be with, and are absolutely beautiful.