A heat dome is baking Arizona and Nevada, where temperatures have soared past 115 degrees this week and doctors are warning that people can get third-degree burns from the sizzling asphalt. At Lake Mead, which supplies water for 25 million people in three southwestern states and Mexico, water levels have plunged to their lowest point since the reservoir was filled in the 1930s. In California, farmers are abandoning their thirstiest crops to save others, and communities are debating whether to ration tap water. In Texas, electricity grids are under strain as residents crank their air-conditioners, with utilities begging customers to turn off appliances to help avert blackouts. In Arizona, Montana and Utah, wildfires are blazing. And it’s not even summer yet. “We’re still a long way out from the peak of the wildfire season and the peak of the dry season,” said Daniel Swain, a climate scientist at the […]