At high currents, the terminal block can get warm. In addition, note that the line voltage is fed to the board so take the proper precautions, especially if the system is referenced with respect to line.
WARNING:
Hot
Surface! Contact can cause burns. Do not touch. Take the proper precautions when
operating.
CAUTION: High
Voltage! Electric shocks are possible when connecting the board to live wires. The
board must be handled with care by a professional. For safety, use of isolated test
equipment with overvoltage or overcurrent protection is highly recommended.