$lightweight_fh = $q->upload('field_name');

# undef may be returned if it's not a valid file handle
if (defined $lightweight_fh) {
   # Upgrade the handle to one compatible with IO::Handle:
   my $io_handle = $lightweight_fh->handle;

   open (OUTFILE,'>>','/usr/local/web/users/feedback');
   while ($bytesread = $io_handle->read($buffer,1024)) {
      print OUTFILE $buffer;
   }
}