In 2019, I happened to be visiting Phoenix on a 115-degree day. I had a meeting one afternoon about 10 blocks from the hotel where I was staying downtown. I gamely thought I’d brave the heat and walk to it. How bad could the heat really be? I grew up in California, not the Arctic. I thought I knew heat. I was wrong. After walking three blocks, I felt dizzy. After seven blocks, my heart was pounding. After 10 blocks, I thought I was a goner.

That experience led me to spend the next three years researching and reporting a book about the dangers of extreme heat and how rising temperatures are reshaping our world. I talked to doctors about how when the core temperature of our bodies rises too high, the proteins in our cells begin to unravel. I sailed to Antarctica to see how changes in ocean temperature accelerate the melting of glaciers, causing seas to rise and flooding coastal cities around the world. I talked to people in the slums of India and in oven-like apartments in Arizona and in stifling hot garrets in Paris. I trapped mosquitoes in Houston and learned about how the spread of dengue fever and malaria is altered by hotter temperatures. I talked to engineers about how heat bends railroad tracks and weakens bridges. In short, I thought I had a pretty good idea about the impacts of extreme heat in our world.

And then, in mid-June, a few weeks before publication of my book, a heat dome settled over the entire Southwest as well as Mexico, breaking temperature records and turning asphalt to mush. I had recently moved to Austin, Texas. Yes, Texas is a hot place. But this was different. We’re talking about a heat index — the combination of temperature and humidity — as high as 120 degrees Fahrenheit.

Events disturbingly similar to what I had reported on in other places several years earlier were playing out in real time around me, like hikers dying of heatstroke and thousands of dead fish washing up on Gulf Coast beaches (hotter water contains less oxygen, making it difficult for fish to breathe). The red-faced desperation on the faces of homeless people living beneath an overpass near me was spookily evocative of the red-faced desperation I’d seen on the faces of people in India and Pakistan.

You can argue that Texas has done this to itself. The planet is getting hotter because of the burning of fossil fuels. This is a simple truth, as clear as the moon in the night sky. No state has profited more from fossil fuels than Texas. Revenues from oil and gas production have long been central to the Texas economy and are at least partly responsible for the more than $32 billion projected surplus in the state’s 2024-25 budget. And Texas is also responsible for emitting more than 600 million metric tons of greenhouse gases into the atmosphere each year, more than twice as much as any other state.

The heat dome made visible the barbarity of the state’s political leadership. More workers die in Texas from high temperatures than anywhere else in the country. Nevertheless, on the very day when it was so hot that I didn’t want to walk outside to check the mail until after dark, Gov. Greg Abbott gave final approval to a law that will eliminate local ordinances requiring water breaks for construction workers. Despite the state’s massive budget surplus, many Texas prisons remain without air-conditioning, turning cells into torture chambers on hot days.

If you are lucky enough and well-off enough, perhaps there is no sense that a life-threatening force has invaded your world. This past week, records were set or tied on four consecutive days as the hottest days ever recorded on Earth. On Monday, I happened to be sitting in an air-conditioned cafe in Austin. Around me, people drank iced coffees and bottled water, seemingly unconcerned as the heat outside beat down mercilessly. In my neighborhood, where a couple tore down a modest house, cut down big shady trees and erected a McMansion with a black roof that sucks up heat, massive compressors for the air-conditioning hang off the side of the house like tactical weapons in the climate war.

In some ways, Mr. Abbott’s callousness is not surprising. Many Texans see extreme heat as a feeble foe. At the height of the Texas heat wave, the official Twitter account for a Texas university football team featured a video of a fully suited player running sprints while dragging a heavy chain. “Working in that Texas heat,” the tweet boasted, followed by a fire emoji. Like risking your life in the heat makes you a real cowboy.

Not far from my house is a gym called “HEAT Bootcamp” (the gym’s marketing pitch: “Join the heat wave”). Here, enduring heat is a sign of inner strength (a throwback to medieval times, perhaps, when heat was linked to masculinity through what the philosopher Thomas Aquinas called “the elemental heat of the semen”).

Fortunately, despite high demand for electricity from everyone cranking their A.C., the Texas grid has held steady, largely because of the enormous number of solar panels that have come online in Texas in recent years. People have flocked to Austin’s green spaces, especially the spring-fed Barton Springs pool, proving the value of cool public spaces. At the Blanton Museum of Art in Austin (where my wife is the director) a hot, lifeless courtyard has been transformed into a shady, welcoming patio by the installation of a dozen elegant 40-foot-high structures in the shape of flower petals — proof, if such proof is needed, that a cool city can be a beautiful city.

Among climate activists and others concerned about the future of the planet, there is a lot of talk now about the need for inspiring stories and hopeful solutions. I agree. We are not doomed. In fact, I think the climate crisis is, above all else, an opportunity to change how we think about our relationship with nature and build a happier, healthier, more just world.

But living under the Texas heat dome has reinforced my view that we have to be cleareyed about the scope and scale of what we are facing. The extreme heat that is cooking many parts of the world this summer is not a freakish event — it is another step into our burning future. The wildfires in Canada, the orange Blade Runner skies on the East Coast, the hot ocean, the rapidly melting glaciers in Greenland and Antarctica and the Himalayas, the high price of food, the spread of vector-borne diseases in unexpected places — it is all connected, and it is all driven by rising heat.

We need to start seeing hot days as more than an invitation to go to the beach or hang out at the lake. Extreme heat is the engine of planetary chaos. We ignore it at our peril. Because if there is one thing we should understand about the risks of extreme heat, it is this: All living things, from humans to hummingbirds, share one simple fate. If the temperature they’re used to — what scientists sometimes call their Goldilocks Zone — rises too far, too fast, they die.

Jeff Goodell is the author of the forthcoming book, “The Heat Will Kill You First: Life and Death on a Scorched Planet.”