Nice pick up! :) I see you have him in with a Red Spotted Severum...I just got me a Texas Cichlid earlier this week, although I paid $10.99 for him, and I have him in with my Red Spotted Severum.
I believe there are aquarium chillers, much in the way there are aquarium heaters. You could always try adding blocks of ice to the aquarium. Other than that, I wouldn't advise doing this, unless your garage was equipped with an air conditioner.
That's pretty amazing!
I was in Tampa, Florida this summer on Honeymoon Island, and I was putting shells in my bag, when this little Green Emerald Crab was in one of them. It was cute, and I still have him, almost a year later.