Cold chain is the process used to maintain optimal conditions during the transport, storage and handling of vaccines, and, food and beverages. The chain begins at the manufacturer and ends with the end use, and most often involves the transportation through thermal and refrigerated packing methods and logistical planning to ensure appropriate condition of the products along each point in the supply chain. The necessities of the item being in the chain determine the temperature and humidity requirements of the chain.

Cold chain has global, regional and local impacts as the very nature of the cold supply chain requires co-ordination in these dimensions of space. An efficient cold chain translates to very less waste for perishable products that enter the supply chain. For vaccines this could mean more vaccines being delivered within the shelf life to prospective end users and for food and beverage, it would result in less food being perished: currently, waste factor in food cold chain is 25%. It is very obvious that an efficient cold chain requires strict control of the atmosphere in the logistics space. To reduce the waste factor, intermittent lapses in the cold chain controls have to be monitored. These generally occur during change in the mode of transportation- ships to trucks, trucks to planes, etc. Monitoring tools have to be used that can track the cold chain at any point in space and time. In conjunction, the control system should take into account the lapses mentioned above.

All of the above mentioned come down grossly to the type of container that is used and method of refrigeration. Reefers account for an increasingly used cargo refrigeration units because they can accommodate a wide range of temperature settings and hence a large number of products. In addition, the cargo handling capacity at around 20 Tons of cargo in standardized dimensions designed to fit the global transport system implies versatility, portability and accessibility. Choice of appropriate color (white to increase the share of ambient light being reflected), power source (separate or integrated), and monitoring tools are essential to an effective cold chain. It is interesting to note that reefers are not designed to lower the temperature, instead they are designed to maintain temperatures. Hence, preparation before cargo is being transported in reefers has to be done with utmost care.

The logistics of cold chain, apart from choice of effective refrigeration units involves establishment of comprehensive logistical process to ensure integrity of the cargo. For that, it is vital to assess the characteristics of the cargo and then maintain pre-transport conditions required for the cold chain. Likewise, geographical proximity, time constraints (perishability), ambient temperatures and the mode of transportation available has to be taken into consideration. Custom procedures and the associated wait times and the final delivery to the destination- which often requires planning of everything from warehousing space, market demand, labor available to traffic flows are other things to be considered. After the cargo reaches the final delivery point, temperature recordings should be make known. This helps set benchmarks, reduce anomalities and hence build trust and credibility.

Cold chain has emerged to being an important aspect of the globalization that manufacturers and customers alike have developed a keen taste on. The growing demand for cold chain requiring products combined with the increasing emphasis on quality  has demanded rigorous standards in cold chain logistics. An efficient cold chain can create happy economic bottom line while enhancing the abstract achievements in terms of customer satisfaction and loyalty.