Heat Index: How hot is it?

As we continue into the hottest days of the year, we tend to keep an eye on the weather reports and temperatures before starting our daily workouts. When you hear a weather report that the current temperature is 90 degrees, and you step outside and it feels like 105 degrees you sometimes wonder why it feels so much hotter? The difference is the heat index.

The heat index is a temperature value that is referred to as the real “feel” temperature or the apparent temperature. The heat index is a combined measurement of the air temperature and the relative humidity. When air temperature is high along with elevated relative humidity the heat index could be pushing to areas of excessive heat and putting anyone exercising or working outdoors at risk of a heat-related illness.

It is a good practice to monitor the heat index when you plan on spending long periods of time outside. One way of doing this is by using the Heat Index Chart. If you know the current temperature and the humidity you can find the current heat index on the chart provided.

For example, if the air temperature is 90 degrees and the Relative Humidity is 60% the heat index would be 100. With a heat index of 100 one should use extreme caution when planning on being outdoors. Knowing the heat index is a helpful tool in preventing heat-related illnesses. This helpful chart provides warnings as the heat index rises.

It is also important to know that the heat index values are for shady, light wind conditions. When exposed to full sunshine the heat index values can increase by up to 15°F.


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