A series of laboratory experiments were conducted to evaluate the relationship between degree of tetrachloroethylene (PCE) mass removal and heating duration, initial dense nonaqueous phase liquid (DNAPL) saturation, and soil grain size. Data were collected to evaluate the impact of postheating sample temperature on PCE concentration and to calculate the thermal diffusivity of the soil. A linear relationship was found between initial DNAPL saturation and duration of the co‐boiling plateau, which occurred at 89 °C ± 4 °C. PCE concentrations were reduced most in samples that were heated beyond dryout, but continued heating for 12 hours beyond that point did not lead to further decreases. Heating samples with initial DNAPL saturations between 4.9% and 39.9% pore space illustrated a positive relationship between initial saturation and final soil concentration for a fixed heating duration. Smaller grain size resulted in lower postheating soil concentrations. Cooling postthermal remedy soils to as low as 20 °C prior to sampling did not affect measured PCE concentrations. An analytical model fit to cooling data indicated that the soil diffusivity values ranged from 1.4 × 10−7 to 1.8 × 10−7 m2/s.