The planet's hotter than it has ever been. July was the Earth's hottest month ever recorded since records began. And the consequences of this warming is increasingly becoming too hard to bear — particularly among those who don't have access to climate control. So what happens to our bodies in times of heat extremes? And what will happen when these extremes become the new 'normal'? It's something the veteran environmental reporter Jeff Goodell explores in his new book Heat: Life and Death on a Scorched Planet.