There are about a hundred people on this board more qualified to speak on this than me, but I think that perch are tougher than we give them credit for.
Last May I put about 150 small perch in a small grow out pond near my yard. From the middle of June until about October we had nothing but hot weather and no rain. The pond shrunk into a puddle of about 20' in diameter, and I literally kept some water in it with a garden hose. Water temps were between 85 and 90 for much of the summer. Finally in September I drained and seined and moved them to an indoor RAS. I don't think I lost any fish.
