Temperatures are skyrocketing for the third straight day across the Eastern US, with officials in cities from Boston to Washington, DC trying to keep residents cool amid outdoor July 4th celebrations. Dozens of daily records are being set as the combination of heat and humidity sends the heat index soaring.
But “how hot is it?” is not as straightforward a question as it seems. And understanding the different heat metrics can be lifesaving, since heat is the number one weather-related killer in the US.
“The problem with temperature alone is that there’s other factors that can cause heat stress,” said Andrew Grundstein, a researcher at the University of Georgia who…