Temperature is an important measurement in watchmaking. Notably for certifications such as the COSC, which measures the precision of a watch at three different temperatures, but also more simply for a building housing a machine park. One degree Celsius difference can correspond to several microns of difference.
In everyday life, temperature is related to the feeling of cold and heat. In physics it measures the degree of agitation of particles. The closer they are to immobility, the closer they are to absolute zero. For temperature, an absolute zero exists, which corresponds to the immobility of particles. A maximum temperature does not scientifically exist.
There are different units used to measure temperature. In the international system, the degree kelvin is used, whose zero corresponds to absolute zero. Another widely used unit is the degree Celsius, where 0 is the melting point of water and 100 is the boiling point of water at sea level.
One kelvin or one degree Celsius is the same quantity. The zero of the kelvin corresponds to -273.15 degrees Celsius and the 0 of the degree Celsius corresponds to 273.15 kelvin.
In some Anglo-Saxon countries the degree Fahrenheit is used. The scale is different from Celsius and Kelvin and a Fahrenheit measurement is also different from both. Twenty degrees Celsius corresponds to 68 degrees Fahrenheit.