History of Thermometers in Medicine The development of accurate clinical thermometers in the late 19th century revolutionized the practice of medicine. Earlier physicians had only crude methods of assessing fever, such as feeling a patient's skin, noting flushed cheeks or measuring pulse rate. The first practical clinical thermometer was invented in 1864 in the United States by Thoma... https://www.newswirestats.com/medical-thermometer-analysis/