Effective mental workload measurement is critical because mental workload significantly affects human performance. A non-invasive and objective workload measurement tool is needed to overcome limitations of current mental workload measures. The objective of this study is to evaluate the efficacy of using thermal imaging of the face to quantify learning and mental workload levels during a novel alpha-numeric task and during simulated driving tasks. To this extent, three studies were completed. The first study quantified the relationship between facial thermal images and mental workload while performing the alpha-numeric task. The second study used thermography to identify optimal workload levels for this same task after learning had occurred. The third study quantified learning and workload of novice and experienced drivers performing scripted driving events in a driving simulator. This study verified that thermography is a reliable and valid way to measure workload for simple tasks. It is a non-invasive and objective method. Thermography showed the capability to identify a sufficient training time for simple or complex cognitive tasks.