Sounds like your aquarium overheated because of a bad heater. (water flow or not, a heater with a temp setting shouldn't reach 86 when set to 81)
It also sounds like because you took your filter out that you may have started a minicycle. (Cloudiness is often cause by bacteria)
One important thing to note, is the higher temperature means the water will hold less oxygen, and with the filter not moving water you may have experianced a DO crash. (Disolved Oxygen) It could be because of those two things your fish asphyxiated.
In hind sight, you should have pretended you were on fear factor or something, and rinse the filter in some of the tank water you took out from the PWC. It's just fish poo, not gonna kill you. Rinse it really well until it's somewhat clean, use fresh tank water when it's too dirty, then replace it when you're done. It's messy and unpleasant, but your fish will thank you.
Hope that helps.