What's a Wind Chill Factor? What about a Heat Index?

• There is an insulating layer of skin covering the human body, which under normal conditions acts as a thermal blanket to keep body heat from escaping. When it is windy, some or all of this layer is blown away, allowing heat to escape, and making the body feel colder. This adjusted apparent temperature is the Wind Chill Factor.

• When the body is hot, it cools itself by sweating. When conditions are hot and humid, the moisture in the air slows the rate at which the body can release its own moisture, thus the heat is trapped in the body, and one feels hotter. The attempt to quantify this perception is the Heat Index.
• The lowest recorded wind chill temperature is -150°F (east Antarctica, July 4, 2003, temp.=-94°F, wind=75mph). The highest recorded heat index reading is 176°F (Saudi Arabia, July 8, 2003, temp.=108°F, rel. humidity=67%).

Video: A Really Cold Day!