Heat kills deadly

[Willito]

Woh, I never thought that I would encounter such problem, but it's a reality. When the lights came on this morning, I noticed 4 colonies of sps, a fairy wrasse, and a blenny have become causualties of the summer heat.
I glanced at the thermometer and it appeared to be at 90C+. All the other corals have shribbled up and not looking so great. I threw on a fan to cool it down right away, but I don't know if it's going to help out the other remainders. I also turned off the halides for the day.

I am a litte lost right now, as to how it got up to 90c+ in a matter of 24 hrs. I understand that it was hot yesterday, but it was also hot days before as well. My heater has been unplugged for weeks now, pumps are still the same. I wonder if it has anything to do with the fact that I recently added a cover onto the sump. Could this lid, which is covering 90% of the sump be the culprit? If so, I hope removing it will cool things down.

Has anyone else experienced this? How do you coupe with this weather if the tank is not in the basement?


-Will