Having an ice-cold drink on a hot day is one of the most refreshing feelings. But for one to access such a drink, it has to be refrigerated first. The idea of refrigeration, according to Live Science, a general knowledge platform, dates as far back as 1000B.C whereby Chinese cut and stored ice. In 500 BC, Egyptians and Indians are said to have left clay pots outside during cold nights to make ice. In 18th century Europe, ice was collected in winter, salted, wrapped in flannel and stored underground to preserve it. However, the process of inventing the refrigeratoris relatively recent and it spanned over many years. It began in 1748 when Willian Cullen, a Scottish Professor developed the idea of creating an artificial cooling medium. It only attracted the attention of a few scientists because it had no practical application. This is according to Who Invented, an online educational website on inventions. In 1805, American inventor Oliver Evans designed a refrigeration machine that used vapor instead of liquid to make things cool. According to ThoughCo, an online general knowledge platform, Evan’s concept of a refrigerator was put to use in 1844 when John Gorrie an American physician used the design to produce ice for cooling the air for yellow fever patients. Before Gorrie’s production of ice, according to Part Select an online educational platform on appliances, American inventor Jacob Perkins built the first practical refrigerator in 1834. It was a closed-cycle device that could compress vapor, thereby operating continuously. The first person to obtain a patent for a practical vapor compression refrigeration system was British journalist James Harrison. According to Wikipedia, the online encyclopedia, Harrison started the process of building a refrigeration system that had elements such as ether, alcohol and ammonia in 1851. The debut of the ice-making machine was in 1854 and the patent for the vapor compression system was granted in 1856. Between 1856 and 1929, refrigerators used ammonia, methyl chloride and sulfur dioxide as refrigerants. Because the gases are toxic, they led to deadly accidents. To solve this problem, according to ThoughtCo, three American companies collaborated and carried out research which led to the discovery of Freon, a less dangerous method of refrigeration. Later it was discovered that Freon was dangerous to the environment, the ozone layer to be specific. According to Live Science, it was Albert Einstein, a renowned physicist who patented an environmental-friendly refrigerator in 1930. Einstein’s refrigerator did not make use of electricity. Over the years, there have been many improvements refrigerators to include functions such as automatic defrosting and ice making. This has made refrigerators multi-functional. Refrigerators now do a lot more than keep things cool. They are used for preserving food, for meat packing, brewing and many other functions.