In the shipment of perishables, air cargo has always been behind the technology curve when compared to other modes. In road or sea freight, continuous cool chains, logging of temperatures in transit, and even the use of modified atmospheres to preserve produce have long been standard. In air cargo, by contrast, many shippers still put their fish, fruit, vegetables or flowers in insulated boxes with a gel pack, and hope for the best.
Source: Air Cargo World, http://aircargoworld.com