Infrared light was discovered in 1800 by Sir Frederick William Herschel. Herschel, born in Hanover, Germany, decided to investigate the temperature of each color of the spectrum produced when sunlight is passed through a prism.To do this, he used three thermometers whose bulbs he blacked out (the better to absorb heat with).erschel, born in Hanover, Germany, decided to investigate the temperature of each color of the spectrum produced when sunlight is passed through a prism. To do this, he used three thermometers whose bulbs he blacked out (the better to absorb heat with).
Body temperature may be abnormal due to fever (high temperature) or hypothermia (low temperature). A temperature over 38Â°C (100.4Â°F) most often means you have a fever caused by infection or illness. It is generally medically accepted that normal body temperature ranges between 36.5Â°C (97.7Â°F) to 37.5Â°C (99.5Â°F).
The NHS says that a normal temperature is around 37C (98.6F), although it depends on: 1  The person. 2  Their age. 3  What they've been doing.  The time of 1  day. Which part of the body you take the temperature from.