Its distribution centers include services such as blast freezing of perishable goods. This is particularly useful in markets for perishable goods, such as groceries. There is some evidence that wealth may have consisted of perishable goods. PT boats lacked a large capacity refrigerator to store sufficient quantities of perishable foods. The consumers get the supply of perishable commodities with lower fluctuation of prices. Offloading the extra freight may not be practical for perishable or hazardous loads. Pickling can preserve perishable foods for months. Particularly smaller shipments of perishable and frozen foods have taken that route. Thawed food should be handled according to the same guidelines as perishable fresh food. She was held fit to carry dry and perishable cargoes. Optimum temperature range for perishable food storage is . The optimum temperature range for perishable food storage is . As they are not smoked or otherwise preserved they are very perishable. In August 2007, Amazon announced AmazonFresh, a grocery service offering perishable and nonperishable foods. Unlike other states, rent, medical services and perishable foods are subject to the excise tax.