I live in Arkansas, so you don't have to tell me about the heat. I make mine up and it stays in my garage which probably gets to about the same temp as your tack room. I have not had any problems with it being in the garage. Due to the heat it does seem to ferment maybe faster than if it were somewhere cooler. I don't see that as a problem though. It just means more fermentation and probiotic health benefits for the birds.