An evaporate cooler might help (if AC is not working, but an AC should work. Check all the filters, rabbit fur can really block filter). Frozen 2 liter bottles full of water can do in a pinch. I'm in arizona and I use an evaporate cooler and it keeps my rabbitry about ~80-85 degrees in the hotter parts of the summer. Misting systems can work if you can't afford an evaporate cooler or AC or the area isnt as enclosed for those other two to work but it probably wouldn't keep it as cool.