Wet-Bulb Temperatures: How Are Extreme Heat and Humidity Outpacing Human Tolerance?

This article was originally published on Oct. 31, 2021 and has since been updated with new information on wet-bulb temperatures.

For thousands of years, Earth has been good to us. The planet has cooperated with our physiology (or, rather, natural selection has shaped our physiology to fit a wide variety of climates) and allowed us to survive just about anywhere we please.

But its generosity is winding down. As we careen toward temperatures that neither we nor any of our ancestors have encountered, the question arises: How hot is too hot?

Extreme Heat Wave Temperatures