Ultra high temperature, universally abbreviated UHT, is a sterilisation process in which a liquid food — most famously milk — is heated to around 135°C to 150°C for a few seconds, then cooled rapidly and packed aseptically. The extreme brevity of the heating destroys all microorganisms and spores while limiting the cooked flavour and nutrient damage that longer heating would cause. UHT milk keeps for months unopened at room temperature, which transformed milk distribution in warm countries and anywhere refrigeration is unreliable. The trade-off is sensory: UHT milk tastes perceptibly more cooked than pasteurised milk, and some heat-sensitive vitamins are reduced. Juices, creams, and soups are also UHT-treated.