Prime has warnings about use with high temp and low O2 because it uses up O2 to work but not that much within recommended dose. Your fish are suffering from O2 deprivation. Get some power heads blowing air or get your fish out of there ASAP until the chemical subsides. I did the same thing once and had to put a bunch of micro bubble wands in the tank to multiple pumps and it worked, I only had 1 tank back then with 30 fish no place to go.