KISS had to postpone their Salt Lake City show in Utah last Saturday night because Gene Simmons had to undergo a medical emergency.
Simmons tweeted last Friday to apologise to fans. He also said, "We will come back and do the show at a later date. The truth is, I have to fly to LA to do a medical procedure. Nothing serious. But it must be taken care of now. Thank you for your good wishes. All is well."