Context: Researchers have recommended certain ultrasound treatment parameters for deep heating; however, we observed different parameters in the clinical setting. Objective: To compare the treatment effect of using observed clinical parameters (OCP) from 8 clinicians to the treatment effect of using the recommended parameters (RP) sited in research. Design: 2 × 2 repeated measures design. Setting: Sports injury research laboratory. Participants: Ten healthy volunteers. Interventions: Two 1 MHz treatment, 1 RP treatment (1.5 W/cm2, 10-min, area-2 to 3 × ERA), and 1 OCP treatment (1.3 W/cm2, 8-min, area 3.9 X ERA) Main Outcome Measure: Tricep surae temperature 3 cm below superficial tissue Results: The RP treatment increase temperature from 36.4 ± 1.0 to 40.3± 2.0°C, which was a greater change than the OCP (36.5 ± 1.2 to 38.2 ± 1.6°C). Conclusions: The OCP treatment resulted in a lower heating affect than the RP. Small change in treatment area, intensity, and duration can have a large effect on temperature change.