Defining heat index

During summer in New Orleans, we hear about the heat index. But what is that exactly?

The heat index is the temperature your body feels, factoring in humidity. When sweat evaporates from your skin, the evaporative cooling process reduces your body temperature, making you feel cooler. However, if the air is already filled with moisture, sweat doesn’t evaporate quickly, and you feel hotter.

Two variables go into the heat index calculation: air temperature and relative humidity. In a humid place like NOLA, summer air temperatures are often in the low 90s, but the heat index can be 20 degrees higher.

– WWLTV, Part of Louisiana Tegna Local