It's the 25th of June and I'm shivering in my lab-issued underwear in Fort Worth, Texas. Libby Cowgill, an anthropologist in a furry parka, has wheeled me and my cot into a metal-walled room set to 40 F. A loud fan pummels me from above and siphons the dregs of my body heat through the...

This is today's edition ofThe Download,our weekday newsletter that provides a daily dose of what's going on in the world of technology. The quest to find out how our bodies react to extreme temperatures Climate change is subjecting vulnerable people to temperatures that push their limits. In 2023, about 47,000 heat-related deaths are believed to...