As a historic heat wave grips much of the world and the United States, no city has become more emblematic of the crisis than Phoenix, where temperatures have exceeded 110 degrees for the past three weeks.Today, the city’s chief heat officer, David Hondula, discusses how the city is adjusting to the new reality of chronic extreme heat — and whether we are adapting to it fast enough.Guest: David Hondula, the director of heat response and mitigation for the city of Phoenix.Background reading: Arizona is used to scorching summers, but a long stretch of days with 110-degree temperatures is straining patience and resources.Weeks of 110-degree days have left the Phoenix fire department scrambling to rescue people overcome by heat — a test for a force already accustomed to tough summers.For more information on today’s episode, visit nytimes.com/thedaily. Transcripts of each episode will be made available by the next workday.