Thank you for submitting your question. I understand your concern and I will be happy to assist you. A unit with mechanical controls, has no exact lowest temperature. You will need to set it, to the lowest setting and check the temperature with a thermometer, placed between some packages to see how cold it gets. The temperature can also vary depending on the load and location of the unit. I hope this helps. Please reply back to this thread if you require further assistance. Thank you for using Manage My Life.