All I can say is what my properly calibrated digital thermometer told me -- 185F degrees. Definitely makes a difference if you don't want dry chicken breasts, which should be cooked to 165F.
I took them out, being more interested in rescuing my food than testing the unit to see how high the temperature might go. Being off by 20 degrees is pretty significant, especially for any kind of meat. I feel that if the manufacturer is not reliable in terms of regulating temperature, caution is in order. I will still use the unit, but, unlike my normal slow cooker, will check on it more often, will protect whatever it is sitting on from scorching, and would not leave it unattended for extended periods of time.