The Southwest is caught under a heat dome. Climate change is making it worse

With upwards of 300 record-high temperatures in jeopardy this week, more than an eighth of the US population — over 40 million people — are on alert across the western US for a long-lasting, potentially lethal heat wave.

With upwards of 300 record-high temperatures in jeopardy this week, more than an eighth of the US population — over 40 million people — are on alert across the western US for a long-lasting, potentially lethal heat wave.