Warm water isn't really in issue. I was at one of our farms over the weekend and the growout ponds were in the mid to upper 80's. Remember, these fish are tropical and can stand temps upwards of 90 degrees without ill effects. What really hurts your fish is continual temperature fluctuations (i.e.- dropping your tank temp from 85 degrees to 80 degrees, back up to 85 etc. etc.).
