In this write-up, we present an analysis of temperature distribution in tomato carton using finite difference approximation. When freshly harvested tomatoes are placed in a rectangular heap, in a surrounding of 35 degree centigrade temperature, the temperature in the center of the heap is about 2.5 degree centigrade higher than outside. The size of heap considered is equal to that typically contained in a 20 kg carton. When the heap is contained in a carton of cardboard, the difference rises to 4 degree centigrade, and 5 degree centigrade, in case of wood. Eight holes, of 20 mm diameter each, are needed to ventilate the carton adequately.