Hotter days are occurring more frequently than before, not just here in the Stateline, but in most spots across the country. The increase in the number of days featuring extreme heat poses an elevated threat to those who are routinely active outdoors, for example, athletes and those who work outside.
A recent study by Climate Central finds that the number of days featuring heat index values of 90° or higher in Rockford has increased by about 18% over the past 40 years, from 22 days per year in 1979 to 26 days per year presently.
Nationwide, the vast majority of the nation has seen a similar trend. From the Deep South to the Gulf Coast, the trend has been extremely unsettling, with many cities reporting as many as 20-30 more days per year with 90°+ heat indices compared to 40 years ago.
The greater number of extremely hot days poses some significant risks, as heat accounts for more deaths than any other weather hazard. Individuals that are particularly vulnerable to the more frequent hot days are those who work outdoors as well as athletes thrust into intense physical activity during the hot summer months.
As dew points rise during the summer months into the 60s and above, it reduces the body's ability to cool by sweating, as the sweat does not evaporate nearly as easily, if at all. On top of that, strenuous activity such as exercise and manual labor generates 15 to 20 times the amount of body heat compared to when we're stationary. This further adds to the heat stress on the body, which, if not properly hydrated could be more prone to heat-related illness.
The full Climate Central report can be read at the link below.