Is storing md5 password in a cookie unsafe?

[eluser]Kraig[/eluser]
Do you know why this isn't working...I'm not sure if I'm getting the value of rmt which is the hashcode

Code:

// Login with cookie
  elseif ( $CI->input->cookie('rmt') ) // If cookie exists
  {
    $hashcode = $CI->input->cookie('rmt'); // Value of cookie
    $q = $CI->membership_model->validateLoggedIn($hashcode);