Daily Archives: July 29, 2013

Wisconsin experienced a small heat wave July 16-19, when heat indices around the state reached above 100 F.

The heat index, or apparent temperature index, indicates how hot it feels. When our bodies get hot, we cool down by sweating. It is not the sweating that cools our bodies; it is the evaporation of the sweat. If the air has a high humidity, then the rate of evaporation is reduced. This hampers the body’s ability to maintain a nearly constant internal body temperature. When the temperature is high and the relative humidity is high, the heat index is high and it seems hotter than it really is. In these cases, the heat index is greater than the actual temperature. Continue reading →