The US 'Heat Index' Could Be Broken in Upcoming Waves A new study says extremely hot days will become much more common in the near future.
In a standard HI chart, heat's effect on humans is measured by the combined air temperature and humidity.
According to co-author Kristina Dahl, this is the first analysis to include the heat index in a global warming study.
The report adds that days across the U.S. where the index pushes past 100 degrees will soon double.
30 years from now, hundreds of U.S. cities may see over a month's worth of these high temperatures.
On some days, it may become so hot that the index will be "incalculable." Co-author and climate analyst Erika Spanger-Siegfried says these kinds of conditions could be "deadly" for humans.
Erika Spanger-Siegfried, via study Erika Spanger-Siegfried, via study