Thermal drift of infrared cameras remains a major problem for the accuracy and repeatability of radiometric measurements. To control the thermal drift, we developed a cold box to adjust the temperature of the FLIR A325sc camera housing. An error diagram is proposed to estimate the optimal camera operating temperature as a function of the ambient temperature for which the thermal drift is properly managed. The effectiveness of thermal drift compensation is examined on both camera functional ranges. The use of a cold box improves the thermal drift compensation efficiency and reduces the non-repeatability of irradiance measurements.