Daniel Gabriel Fahrenheit divisible into many fractions. It is because of the scale's redefinition that normal body temperature today is taken as 98.6 degrees, whereas it was 96 degrees on Fahrenheit's original scale. The Fahrenheit scale was the primary temperature standard for climatic, industrial and medical purposes in English-speaking countries until the 1970s, nowadays replaced by the Celsius scale long used in the rest of the world. Daniel Gabriel Fahrenheit Daniel Gabriel Fahrenheit FRS (; ; 24 May 1686 – 16 September 1736) was a Dutch-German-Polish physicist, inventor, and scientific instrument maker. Fahrenheit was born in Danzig/Gdańsk, a predominantly German-speaking Hanseatic city in
Medical thermometer is less of a problem with a coloured liquid. In the 1990s it was decided that mercury-based thermometers were too risky to handle; the vigorous swinging needed to "reset" a mercury maximum thermometer makes it easy to accidentally break it and spill the moderately poisonous mercury. Mercury thermometers have largely been replaced by electronic digital thermometers, or, more rarely, thermometers based on liquids other than mercury (such as galinstan, coloured alcohols and heat-sensitive liquid crystals). Phase-change thermometers use samples of inert chemicals which melt at progressively higher temperatures from 35.5 °C to 40.5 °C in steps of 0.1 °C. They