What is commonly used to cool products during flight when traditional methods are insufficient?

Using dry ice to cool products during flight is a common practice, particularly in the transportation of perishable goods or temperature-sensitive pharmaceuticals. Dry ice, which is solid carbon dioxide, sublimates at -78.5 degrees Celsius (-109.3 degrees Fahrenheit), providing a very effective cooling medium that is considerably colder than traditional ice or water-based cooling methods. This extreme temperature helps maintain required low temperatures for products that must not exceed certain limits to preserve their quality and safety.

Compared to other cooling methods, dry ice is efficient as it does not leave behind any moisture that could potentially damage sensitive items when it melts, unlike traditional ice or gel packs. Liquid nitrogen, while also very effective for certain applications, is not as commonly used for general commercial shipping due to its handling requirements and regulatory restrictions. Gel packs can provide temporary cooling but typically do not achieve the low temperatures that dry ice can maintain. This makes dry ice the preferred choice when long-term cooling under stringent temperature control is necessary during transit.