Unfortunatly my fish aren't liking the hot weather this year. Last year I was lucky enough to not lose a single fish, this week I've already lost 3. All my tanks are in my bedroom, and well overheating. They're at an average of 31 C now. All heaters are unplugged, lights are on at a min. and only 1 out of the 3 per tank. Fans are pointed at the tanks, and the airation is at max. Not much to do now but hope ... and it's only getting warmer over the next days.
Ice cubes or heavily cooled water is not something I will try. It's usually not the hot water that kills the fish, but the change in temperature. Being cool blooded animals they take on the temperature of the enviroment, and dropping from 31C to say 26C (if chilled by icecubbes) is not something that's a good thing. They might like it because obviously the cooler water is much much better than the hot water for them, but if this happens to often (and a 10 minute 'refreshment' a day isn't gonna keep them alive for me) their bodies won't take kindly to it.
With my bedroom temperature being at 33C still (midnight now), and the tank water at 31C ... I'm seriously concidering buying an airco (even though I only spend about 12 weeks a year here)