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 normal human body temperature is often stated as 36.5â37.5 Â°C (97.7â99.5 Â°F). In adults a review of the literature has found a wider range of 33.2â38.2 Â°C (91.8â100.8 Â°F) for normal temperatures, depending on the gender and location measured.n addition to varying throughout the day, normal body temperature may also differ as much as 0.5 Â°C (0.9 Â°F) from one day to the next, so that the highest or lowest temperatures on one day will not always exactly match the highest or lowest temperatures on the next day.