Even on the warm setting, I doubt it would be cool enough. I was Serve-Safe Certified (A Cullinary School thing) over a year ago. And food must be kept above 140 degrees to slow bacteria growth, so a crock pot wouldn't be safe if it didn't at least keep food 140 degrees.
Here is a quote I found on the subject.
"After the food is cooked and ready to serve, keep it warm enough to stop any germs from growing. There is special equipment for this. You must turn on steam tables, soup warmers, and heated surfaces before you need them so that they will be hot enough when you put the cooked food into them. Set the temperature control a little above 140° F, and then check the food with your metal stem thermometer to make sure the food stays at least at 140° F at all times. Stir liquid foods (like soups and gravies) so they don't get cold on top. Covers on the pans will help to keep the heat in and the food warm enough. Do not try to heat cold foods in these warmers. Hot hold food above 140° F."
Here is a quote I found on the subject.
"After the food is cooked and ready to serve, keep it warm enough to stop any germs from growing. There is special equipment for this. You must turn on steam tables, soup warmers, and heated surfaces before you need them so that they will be hot enough when you put the cooked food into them. Set the temperature control a little above 140° F, and then check the food with your metal stem thermometer to make sure the food stays at least at 140° F at all times. Stir liquid foods (like soups and gravies) so they don't get cold on top. Covers on the pans will help to keep the heat in and the food warm enough. Do not try to heat cold foods in these warmers. Hot hold food above 140° F."