WASHINGTON POST • July 18, 2023
As the Northern Hemisphere approaches summer’s peak, heat is testing the limits of human survival in Earth’s hottest spots – and demonstrating the extremes that are increasingly possible and probable against the backdrop of accelerating global warming. “We know these extreme temperatures are killing people right now,” said Cascade Tuholske, an assistant professor at Montana State University. Research has shown the human body loses its ability to cool itself via sweating at 95 degrees on a scale known as the wet bulb global temperature, which factors in a combination of temperature, humidity, wind speed, sun angle and cloud cover. A study published last year estimates that bar to be even lower, closer to 88 degrees even for young and healthy people.