Body temperature measurement from the 17th century to the present days

One of the first measurements in the health sector was probably the body temperature, whose increase, the so-called fever, was related to an illness condition. A fever develops as the body’s natural way of reacting to and fighting infection. Attempts to standardized temperature measurements were developed in the 17 th century when physicians started to think of measuring this parameter and to develop new devices for assessing the body temperature. This scientific field has its origins in the works by Florentine scientists in the 1600s, meanwhile the development of today’s thermometers and temperature scales began in the early 18th century. This paper describes an invention of the Grand Duke Ferdinand II de’ Medici on display in the Galileo Museum in Florence, the clinical frog thermometer,tied to the wrist or the arm of the patient with the head of the frog facing upward. The performances of this device based on the Galilean thermometer principles, are compared with today’s mercury and infrared thermometers.