Time and temperature control are critical to maintaining food safety, both when heating foods up and cooling them back down. Simply setting a pan of hot food in the cooler is not enough to ensure safety. Rather than investing in an expensive chiller, you can set cooling paddles in the food to help cool them from the inside out. To properly use a cooling paddle, fill it with water and freeze it over night. Do not fill it completely full, since water expands as it freezes; only fill it to the handle. Once frozen, it can be placed in a pan of hot food and on a cooler shelf. You will want to stir the paddle every so often to redistribute the heat and cold. Different size paddles are available for larger or smaller quantities of food.
After each use, you will want to run the paddle through the dish machine to clean off any food residue. In order to maximize freezer space, you can also acquire some wall brackets and hang them on the cooler wall to freeze.