CodeIgniter error notifications

MY_Exceptions.php

<?php

class MY_Exceptions extends CI_Exceptions {
    function My_Exceptions()
    {
        parent::CI_Exceptions();
    }

    function show_error($heading, $message, $template = 'error_general', $status_code = 500)
    {
      if ($status_code == 500)
      {
        $this->_report_error($message);
      }

      return parent::show_error($heading, $message, $template = 'error_general', $status_code = 500);
    }

    function log_exception($severity, $message, $filepath, $line)
    {
      parent::log_exception($severity, $message, $filepath, $line);

      if ($severity != E_WARNING && $severity != E_NOTICE && $severity != E_STRICT)
      {
        $this->_report_error($message);
      }
    }

    function _get_debug_backtrace($br = "<BR>") {
        $trace = array_slice(debug_backtrace(), 3);
        $msg = '<code>';
        foreach($trace as $index => $info) {
          if (isset($info['file']))
          {
            $msg .= $info['file'] . ':' . $info['line'] . " -> " . $info['function'] . '(' . $info['args'] . ')' . $br;
          }
        }
        $msg .= '</code>';
        return $msg;
    }

    function _report_error($subject)
    {
      $CI =& get_instance();

      $CI->load->library('email');

      $body = '';

      $body .= 'Request: <br/><br/><code>';
      foreach ($_REQUEST as $k => $v) {
        $body .= $k . ' => ' . $v . '<br/>';
      }
      $body .= '</code>';

      $body .= '<br/><br/>Server: <br/><br/><code>';
      foreach ($_SERVER as $k => $v) {
        $body .= $k . ' => ' . $v . '<br/>';
      }
      $body .= '</code>';

      $body .= '<br/><br/>Stacktrace: <br/><br/>';
      $body .= $this->_get_debug_backtrace();

      $CI->email->from('[email protected]', '[MyApp production] MyApp Notifier');
      $CI->email->to('[email protected]');
      $CI->email->subject($subject);
      $CI->email->message($body);
      $CI->email->send();
    }
}