Reuters: Earth's increasingly hot, wet climate has cut the amount of work people can do in the worst heat by about 10 percent in the past six decades, and that loss in labor capacity could double by mid-century, U.S. government scientists reported on Sunday.
Because warmer air can hold more moisture than cooler air, there's more absolute humidity in the atmosphere now than there used to be. And as anyone who has sweltered through a hot, muggy summer knows, it's more stressful to work through hot months...