An immersion blender includes a housing, and a battery pack is selectively coupled to the housing. An implement includes a shaft cover that extends from the housing along an axis. A rotatable shaft is located in the shaft cover. A motor is located in the housing and is operably connected to a first end of the shaft. An implement tool is operably connected to a second end of the shaft. A user interface includes a power button and a lock button that are configured to activate the motor only while the power button and the lock button are simultaneously held.