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 body temperature of a person varies depending on gender, recent activity, food and fluid consumption, time of day, and, in women, the stage of the menstrual cycle. Normal body temperature can range from 97.8Â° F (or Fahrenheit, equivalent to 36.5Â° C, or Celsius) to 99Â° F (37.2Â° C) for a healthy adult.ody temperature may be abnormal due to fever (high temperature) or hypothermia (low temperature). A fever is indicated when body temperature rises above 98.6Â° F orally or 99.8Â° F rectally, according to the American Medical Association.