The appropriate temperature for cold chain transportation will depend on the type of product being transported. Typically, these fall into two categories: refrigerated and frozen. Refrigerated is defined as +2°C to +8°C (+35.6°F to +46.4°F), and it is often difficult to stay within this range. Knowing the temperature range of the product can help in the successful delivery and function of the product. The acceptable temperature limits of the product may be higher than +8°C and can be used in defining the acceptance criteria for the qualification. Frozen conditions usually do not vary since dry ice is typically used to meet these requirements. Dry ice sublimes (turns from a solid to gas) at -78.5°C (-109.3°F) was ideal for transporting COVID vaccines.