Corrosion of Conformity canceled their scheduled appearance at Ground Zero in Traverse City, Michigan Sunday night as drummer Reed Mullins remained in a Pittsburgh hospital where he was being treated for heat exhaustion.  A statement from the band read:  "We are still in Pittsburgh waiting for our drummer to be released from the hospital. We're all wishing Reed a speedy recovery and hope we can resume the tour as soon as possible."  The band also had to cancel Saturday night's show in Flint, Michigan.  The headlining act for the tour, Clutch, has gone on with the shows in COC's absence, no word yet on when COC will rejoin the tour.