A surgical instrument includes a handpiece including a housing and a motor disposed in the housing. An end effector assembly is operably coupled to the handpiece. The motor actuates the end effector assembly. A temperature measurement assembly is in the housing. The temperature measurement assembly measures a temperature of the motor. The temperature measurement assembly includes a printed circuit board (PCB) including an orifice extending through the PCB. An infrared (IR) sensor is on the PCB. The IR sensor transmits IR light to a temperature measurement location of the motor through the orifice of the PCB. The IR sensor detects IR light reflected from the temperature measurement location of the motor to determine a temperature of the temperature measurement location of the motor.