PHOENIX (AP) — Extreme temperatures like the ones blistering the American West this week aren't just annoying, they're deadly.

The record-breaking temperatures this week are a weather emergency, scientists and health care experts say, with heat responsible for more deaths in the U.S. than all other natural disasters combined. With more frequent and intense heat waves likely because of climate change and the worst drought in modern history, they say communities must better protect the vulnerable, like homeless people and those who live in ethnically and racially diverse low-income neighborhoods...