Human comfort depends essentially on 4 factors:
  a) Air temperature
  b) Humidity
  c) Air velocity
  d) Radiant heat

These parameters, allow us to determine the sensation of heat by a human, in a particular place. A high dependency on humidity, is related to the human transpiration phenomenon, which is a body temperature control mechanism. Due to transpiration, the evaporation of water (sweat) removes heat from our body, lowering the skin temperature. 

However, the evaporation rate depends on the relative humidity that exists in the surrounding air. The higher the humidity, the lower the transpiration, resulting in a sensation of a higher temperature.

In hot and humid climates it is important to take into consideration the TWL (thermal Work Limit). This limit is used to protect workers or athletes, in hot and humid climates such as those that exist in the Middle East.

The combination of high temperature and high humidity, is particularly dangerous for a worker, and should therefore be monitored in a continuous mode, enabling us to stop the work, if the Heat Index value reaches a predefined value.

EWEN developed its own Heat index Monitoring System, that utilizes temperature and humidity sensors in the field (in the work environment) and its web based platform (available on any web-enabled device).


Image 1 - Heat Stress Index