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

by Jeff Goodell

Until we figure out a way to suck massive amounts of CO2 out of the sky, we will be stuck with a hotter planet.

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.

“We’re all in the storm, but we’re not in the same boat,” Heather McTeer Toney, the former mayor of Greenville, Mississippi, said during testimony before the US Congress. “Some of us are sitting on aircraft carriers while others are just bobbing along on a floatie.”

In Africa and the Middle East, studies have found a link between higher temperatures and the outbreak of civil war.

Even if we transition fairly quickly to clean energy, half of the world’s human population will be exposed to life-threatening combinations of heat and humidity by 2100. Temperatures in parts of the world could rise so high that just stepping outside for a few hours, another study warned, “will result in death even for the fittest of humans.”

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.

In many places in the world today, heat is rising faster than our ability to adapt to it.

“The largest single global change that threatens food security is high temperature.”

If the Covid-19 pandemic demonstrated anything, it was how quickly and easily people were able to normalize the deaths of others, especially if they were old, sick, or otherwise living on the margins. There were a thousand deaths a day from Covid in the US alone.