Abstract: A temperature-controlled pharmaceutical device includes a substantially enclosed and thermally insulated structure having at least one port which allows access to an enclosed storage area which has a storage temperature. A thermopile heat exchange unit is provided for heating and cooling the storage area in response to signals provided by temperature sensors and a window detector. The storage area is maintained at a temperature between upper and lower predetermined limits. When these limits are exceeded for a predetermined length of time, a visual display is actuated to warn that the substances should be discarded immediately. After signaling an alarm, the indicator is reset by way of a lock switch. The lock switch discourages unauthorized resetting. An energy saving switching mechanism is provided for overriding the heat exchanger circuitry when the port to the enclosed area is open, preventing unnecessary discharge of the battery pack.