The Heat Will Kill You First: Life and Death on a Scorched Planet

by Jeff Goodell

When the next pandemic hits, the chances are good it will be caused by a pathogen that leapt from an animal that was seeking out a cooler place to live.

If there is one idea in this book that might save your life, it is this: The human body, like all living things, is a heat machine. Just being alive generates heat. But if your body gets too hot too fast—it doesn’t matter if that heat comes from the outside on a hot day or the inside from a raging fever—you are in big trouble.

There is a lot of confusion about the relationship between water and heat exhaustion and heatstroke. Water is necessary to keep sweat flowing. If you get dehydrated, you can’t sweat. And if you can’t sweat, you can’t cool off. But drinking water does not in itself cool off inner-core body temperatures. Put another way, dehydration can exacerbate heat exhaustion and heatstroke, but you can still die of heatstroke and be well hydrated.

“Both heat exhaustion and heatstroke can occur in the absence of dehydration. We can speculate that proper hydration can, however, delay heat exhaustion because dehydration exacerbates heat exhaustion. But proper hydration cannot prevent heatstroke.”

A well-hydrated human can sweat up to three quarts per hour, but no matter how much water you drink, your body can only replace about two quarts of water per hour—so if you are in a hot place for a long time, dehydration is a concern.

The only effective treatment for heatstroke is to get a person’s core body temperature down, fast. A cold shower or bath, or tubs (or, as I mentioned in the prologue, body bags) of ice, is one way to do this. Another is to quickly cool places on the body where, because of the structure of our veins, a lot of blood circulates close to the surface: the bottoms of the feet, the palms of the hands, the upper part of the face.

On average, terrestrial creatures are moving nearly twenty kilometers every decade. Marine creatures, who are largely free of barriers to seeking cooler waters, are moving four times faster than land-based animals.

Seventy percent of the Earth’s water is frozen here in ice sheets that can be nearly three miles thick.

70% of *fresh water*. Fresh water 3.5% of earth’s water.

The Drake is widely recognized as the most dangerous passage in the world for ships.

By one count, half the people who have ever lived have been killed by mosquito-borne pathogens.

The mosquito was a female—only females drink blood, which they need to produce their eggs.

An even more deadly strain of the same bacteria, Vibrio vulnificus, while rare, has been detected more and more frequently in bays and estuaries on the East Coast, particularly around Chesapeake Bay, as well as in Florida in the aftermath of Hurricane Ian in 2022. Vibrio vulnificus, if you happen to eat it in raw or undercooked shellfish, might give you a bad stomachache (in rare cases, it can be fatal). If the bacteria gets in a cut or wound, however, it becomes a flesh-eating horror and kills one in five people who come in contact with it.

Why are bats so good at harboring deadly viruses? For one thing, they have immune systems tolerant of infection that allow them to host a wide variety of viruses without getting sick. They live long lives (up to forty years), giving them plenty of time to spread disease. They are very mobile—some species range thirty miles or so each night in their hunt for food. And more important, as the climate warms, they can relocate. “Climate change is affecting bats in profound ways,” said Plowright. “Many bat species are insectivorous, and so climate change has a big impact on their food sources, as well as on their physiological stress and where they live and how they interact with humans.”

Between 1940 and 1980, warm-climate states in the South gained twenty-nine electoral college votes, while the colder states of the Northeast and the Rust Belt lost thirty-one. Among the first to figure this out was Richard Nixon, who wooed these Sun Belt conservatives in the 1960s with anti–civil rights messages and racial dog whistles. American politics has never been the same since.