As climate change fans hotter and longer heat waves, breaking record temperatures and leaving dozens dead, the poorest Americans suffer the hottest days with the fewest defenses. Air conditioning, once a luxury, is now a matter of survival. When dangerously high temperatures engulfed Phoenix, almost all of those who died indoors didn’t have air conditioning. As cities like Denver, Portland and Seattle, which are accustomed to cooler summers, and other cities nationwide face a new barrage of heat, low-income households, renters and people of color are far more likely to suffer the sweltering heat without cooling