When we measure length, we use a ruler; when we measure time, we use a clock; and when we measure temperature, we use a thermometer.
Thermometry is the process of measuring temperature. The first practical measurement of temperature was developed by Daniel Gabriel Fahrenheit (1686-1736). He invented the first mercury thermometer where the standardized temperature scale was in Fahrenheit.
Another temperature scale is Celcius, invented by Anders Celsius (1701-1744). The Celsius scale is known as a Universal System Unit, it is used throughout science and in most countries. Fahrenheit and Celsius are just two methods to measure temperature, there are others.
According to the thermometer, at standard pressure, water freezes at 0°C or 32°F and water boils at 100°C or 212°F. On an average, the human body has a temperature of about 36.8°C or 98.2°F.
Heat and Temperature