Cold chain refers to all kinds of fresh food in the whole process of production, transportation, sales and storage, the temperature is controlled within the range of O℃~4℃ ~ 4℃, and the freshness and taste of the food are maintained to the maximum extent. Cold chain in a broad sense refers to this process and the equipment to realize this process. The food industry was the first industry to introduce the concept of cold chain, and now it has been applied in many fields such as medicine, aerospace and so on.

Drug cold chain:

1. Drug cold chain refers to a special supply chain management system for refrigerating drugs and other temperature-sensitive drugs. The whole storage and circulation process from the finished product warehouse of the production enterprise to the use must be carried out in a specified temperature environment (temperature control system) to ensure the quality of drugs.

2. The cold chain of drugs involves four links: low-temperature production, low-temperature transportation and distribution, low-temperature storage and low-temperature sales. Cold chain drugs have entered the cold chain process since they were produced in pharmaceutical factories. It is transported to the sales terminal through storage nodes and circulation channels, and finally sold to consumers.

3. As a systematic project, the drug cold chain has become a long-term and important infrastructure for all drug production, wholesale, retail and consumption terminal enterprises and institutions.

Food cold chain:

1. Food cold chain refers to a special supply chain system in which perishable food is always in the low-temperature environment necessary for the product after it is purchased or captured from the place of origin, during the processing, storage, transportation, distribution and retail of the product, until it reaches the hands of consumers, so as to ensure food quality and safety, reduce loss and prevent pollution.

2. At present, the range of foods applicable to the cold chain includes:

Primary agricultural products: vegetables and fruits; Meat, poultry and eggs; Aquatic products; Flower products.

Processed food: quick-frozen food; Packaged cooked food such as poultry, meat and aquatic products; Ice cream and dairy products; Fast food ingredients.

3. Food cold chain is a low-temperature logistics phenomenon based on refrigeration technology. Therefore, the construction of cold chain requires comprehensive consideration of various problems involved in production, transportation, sales, economy, technology, etc., and coordination between them to ensure the safety of perishable food in the process of processing, transportation and sales. It is a high-tech cryogenic system engineering.