The TMP100 / TMP100E (PC868) Infrared Thermometer comes pre-configured from the factory so you should not have to adjust the baseline temperature function under normal conditions.

The baseline temperature function is there to account for the variance in temperature readings. For example, when you measure someone's temperature using the traditional mercurial thermometer, you may get a reading of 98 degrees Fahrenheit. However, you may get a slightly different reading with an infrared thermometer (i.e. 97 degrees Fahrenheit).  Then all you have to do is take the difference, and set the baseline temperature at -1 degrees Fahrenheit. This will ensure your thermometer reads the temperature properly.

Normal temperatures vary by person and location of measurement. To define a baseline, take measurement of the same body location for at least two weeks. 
I'd also like to assure you that our medical grade precision is certified accuracy to within + or - .5 degrees Fahrenheit. 

To set your baseline temperature, please refer to the following video.