In 1612, the first theroscope was invented by Italian inventor Santorio Santorio. It was the first thermometer that was designed to be put in a patient's mouth.
Daniel Gabriel Fahrenheit was a german scientist. He created the alcohol thermometer in 1709 and the mercury thermometer in 1714. Another thing that he created is the Fahrenheit Scale. This scale was used to record changes in temperature.
Then, in 1848 Lord Kevin created the Kevin Scale. The Kevin Scale measures the extremely hot and cold temperatures. The thermometer has changed or world. For example, now we know if food is properly stored and how hot or cold it is outside.