Refrigerated transport is a form of climate-controlled transportation which is designed to maintain a cool or frozen temperature, depending on the product being transported. The development of refrigerated transport was a key step in the development of modern food safety, since this form of transport ensures that foods stay at safe temperatures as they are shipped, and it has a number of other uses, from medicine to physics. Many shipping companies offer this type of transport for an additional cost, and some companies actually specialize in refrigerated transport.
Many people have engaged in the crudest form of refrigerated transport, which involves packing the temperature-sensitive product into a cooler or case with ice packs, dry ice, or loose ice. The ice keeps the temperature cold during shipping for a length of time which can vary from a few hours to a few days. This can be used to move a small quantity of a material, such as soft drinks for a picnic or biological samples from the site of an epidemic.
On a larger scale, refrigerated transport requires a refrigerated vehicle. Refrigerated trucks, train cars, and cargo holds use massive compressors and refrigeration equipment to maintain a constant temperature which can be adjusted to accommodate specific products. For example, some vaccines need to be shipped at very cold temperatures, while produce may simply need to be kept below ambient temperatures so that it does not ripen too quickly or become rotten.
This type of transport tends to demand a lot of fuel, because it takes energy to keep the shipping container cool during transit, especially if icy temperatures are needed. The fuel costs and the base cost of building a refrigerated unit for shipping can make refrigerated transport more expensive than conventional shipping, especially since the shipping company may also need to follow special precautions. Refrigerated trucks, for example, are usually not driven in extremely hot weather, because the refrigeration system could potentially fail when faced with very high temperatures.
Most users of refrigerated transport are large companies and institutions, because individuals rarely require huge volumes of refrigerated materials. Hospitals and medical research facilities rely on this type of transport for specialized medical supplies like vaccines and drugs, while scientific researchers use refrigerated shipping to transport certain chemicals and supplies which are vulnerable to temperature variations. Refrigerated transport is also a huge part of the global food industry, ensuring that fish, meat, dairy products, and fragile produce can be safely carried across great distances to satisfy hungry consumers.