Manufacturers' recommended temperatures for pharmaceuticals were compared with actual field temperatures that the medications were exposed to during the winter months of December and February in the Republic of Korea. Two daily temperatures of field pharmaceuticals were taken in a M577 armored aid station. These temperatures were then averaged and compared with the ambient high and low for that day. The total data collected during the month of December yielded a mean pharmaceutical temperature of 57.50 degrees F with a standard deviation of 5.37. This result showed that the heating unit in the M577 was able to keep the medications 15.07 degrees F warmer than the mean high and 30.77 degrees F warmer than the mean low for the temperatures collected. For February, the mean temperature of pharmaceuticals was 49.25 degrees F with a standard deviation of 5.89. This temperature was 11.37 degrees F higher than the mean high and 33.00 degrees F higher than the mean low. For both the months of December and February, the heating unit in the vehicle tested was not able to meet manufacturer's specifications for more than 90% of the medications reviewed.