Devices for detecting heating under a patient return electrode

A system for predicting the temperature under a return electrode in a monopolar electrosurgical system, comprising:

• a detecting apparatus adapted to connect to a power source including:
• an analog circuit including:
• a heat generating resistor;
• and
• a temperature sensor;
• wherein said heat generating resistor and said temperature sensor are in thermal communication;
• a comparator configured to compare said change in temperature with a threshold value;
• and
• an alarm circuit configured to produce an advisory signal;
• wherein the heating and cooling properties of said analog circuit are proportional to the heating and cooling properties of skin at the return electrode, wherein said detecting apparatus predicts skin temperature of the patient at said return electrode of said monopolar electrosurgical system without contacting the patient, and wherein said alarming circuit alerts the user when the predicted skin temperature exceeds the threshold value.