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).
Normal human body temperature varies slightly from person to person and by the time of day. Consequently, each type of measurement has a range of normal temperatures. The range for normal human body temperatures, taken orally, is 7002309950000000000â 36.8Â±0.5 Â°C (7002309927777777777â 98.2Â±0.9 Â°F).he 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.