Blood cells, vaccines, and other drugs and biological products should be kept at a temperature within certain range. In this paper. a medical thermoelectric cooling kit is introduced. The kit keeps medical products at temperatures between 6 and 10 degreesC while being stored or transported. This range is within the standards recommended by WHO to keep biological, medical and food products. Tests were carried out under various environmental temperatures in laboratory conditions as well as outside the laboratory and on a transportation vehicle. Under all these conditions, the kit provided cooling at a satisfactory level. This paper presents the technical specifications of the kit, theory of its operation, and test results. The kit is supported with a microprocessor unit. The block diagram of the microprocessor program is also presented in the paper. (C) 2002 Published by Elsevier Science Ltd.