What is the difference between air temperature and apparent temperature?
We often use the air temperature as an indicator of how comfortable we will feel when involved in sports or other physical activities. However, the air temperature is only one factor in the assessment of thermal stress. In climates where other important factors, principally humidity, can vary widely from day to day, we need more than just the temperature for a more realistic assessment of comfort. However it is useful to be able to condense all the extra effects into a single number and use it in a similar way to the way we use the air temperature. The Wet Bulb Globe Temperature (WBGT) and the Apparent Temperature are indices which attempt to do this.
