Instrument assisted soft tissue mobilization (IASTM) and superficial heat have reportedly increased range of motion and perceived patient comfort. The ThermoStim provides IASTM and superficial heat simultaneously. Only one study (Guffey, et al., 2013) has been published using the ThermoStim. The purpose of this study was to determine if the range of motion of the hamstrings can be increased utilizing IASTM, and whether superficial heat would create an additional increase in range of motion and perceived patient comfort. Thirty college-aged student-athletes (15 males, 15 females) participated. Pre- and post-treatment range of motion was measured by goniometry with the hip flexed to 90° with passive knee extension. A statistically significant difference existed between pre- and post-treatment range of motion for both treatment times. There was no significant difference between groups due to the inclusion of superficial heat for range of motion or perceived patient comfort.