With Texas being known for its hot — and we mean hot — summers and temperatures in the 100s, those following the weather forecasts will probably hear meteorologists frequently mention the heat index.
But what exactly is that and why does it matter?
The heat index, also referred to as the “apparent temperature,” is what the temperature feels like to the human body and is a major factor in determining whether a heat advisory is issued, according to the National Weather Service.
It’s calculated using air temperature and relative humidity, which compares the amount of water the air can hold at the current temperature with the actual amount of water in the air.
When a person gets hot, the body’s response to cool itself is to sweat and the cooling occurs when the perspiration evaporates off the skin.
However, if the sweat can’t evaporate due to the moisture already in the air, the body has a harder time regulating its temperature and retains the heat, according to the weather service.
In simpler terms: The human body feels warmer when its humid (and cooler in arid conditions).
Sometimes there isn’t much difference between the air temperature and the heat index but other times, especially when there’s a lot of moisture in the air from recent rain, there’s a larger gap.
As the days get longer and people are spending more time outside, practicing heat safety becomes especially important on days with higher heat indexes.
Some good practices for staying safe in the heat include drinking plenty of water, wearing sunscreen, staying in the shade when possible and knowing the signs of dehydration.
