Abstract: A portable heater/cooler system comprises a thermal electric module conducting a current through the module; a heater/cooler cavity coupled to the thermal electric module; a variable speed fan for blowing air over the thermal electric module and into the cavity; a first temperature sensor coupled to the thermal electric module for measuring the temperature of the module; a second temperature sensor coupled to the heater/cooler cavity for measuring the temperature in the cavity; and a microprocessor for adjusting a speed of the fan and the current flow through the thermal electric module as a function of the measured temperatures of the thermal electric module and the cavity.