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