Hundreds of blue, green and grey tents are pitched under the sun’s searing rays in downtown Phoenix, a jumble of flimsy canvas and plastic along dusty sidewalks. Here, in the hottest big city in America, thousands of homeless people swelter as the summer’s triple digit temperatures arrive.

An unusually early and long-lasting heat wave brought more triple-digit temperatures on Wednesday, June 16, 2021, to a large swath of the U.S. West, raising concerns that such extreme weather could become the new normal amid a decades-long drought.