Cold chain logistics is a very complicated issue. Many foods are picked up when meat is slaughtered from animals, there is a certain S.O.P. to save. But because the whole industry chain is very long, many step will affect the safety of food. Whether it is eating fresh food, or using vaccine drugs, it needs to be transported through the cold chain.
Tai, Chih-Chung, "Cold Chain Logistics Management" (2018). ICEB 2018 Proceedings (Guilin, China). 84.