The thermometer in the truck says a hundred and four. It always says something like that in the middle of the afternoon, because it sits under the windshield in the sun, and nobody in this town believes it. What we believe is the feeling when the door opens. The air that comes in is not hot the way an oven is hot. It is hot the way a wet towel is hot, heavy and close, and it has been sitting on the bay all day waiting for you. You put the key in and the seat belt buckle burns your fingers and the steering wheel is something you hold with two knuckles until the vents catch up. That is peak heat on the ship channel: not the number, the weight.
A hundred degrees is a strange threshold, because it is roughly the temperature of the inside of your body. Your skin sits a little cooler than that, somewhere in the low nineties, and as long as the air is cooler than your skin, your body can push heat out into it the ordinary way, the way a cup of coffee cools on a table. Once the air is hotter than your skin, that stops working. The air is now warming you. The only trick you have left is sweat: water leaves your skin as vapor and carries heat with it, and it carries a surprising amount. Every gram of sweat that actually evaporates takes something over five hundred calories of heat away with it, which is more than it would take to bring that same gram of water from ice-cold to boiling. Sweat is the only defense the body has past that line, and it is a good one on a dry day in the desert and a poor one here.
Here the air is already carrying nearly as much water as it can hold. The bay breathes all day, and by late afternoon the dew point sits in the seventies, which means the sweat on your arm has nowhere to go. It beads and runs instead of evaporating, and sweat that runs off you has done nothing; only the sweat that vanishes has cooled you. Weather people fold the two numbers together into a heat index, the temperature it feels like, and on a bad afternoon that number runs well past the one on the thermometer. There is a plainer measure called the wet-bulb temperature, which is what a thermometer reads when its bulb is wrapped in a wet cloth and the water is allowed to evaporate. It is the temperature your body can actually reach by sweating. When the wet-bulb reading gets close to body temperature, there is no shade that saves you. We do not get to that line on the bay. We get near enough to it to understand why the people who work outside here drink water by the gallon and take their breaks in the truck with the engine running.
There is a reason turnaround crews start before dawn in summer, and it is not ambition. It is the sun. A crew that comes in to take a unit apart works in long sleeves and hard hats on steel that has been soaking up light since morning, and the people who run those jobs on the channel learn to put the heaviest work at the front of the day, before the pipe is too hot to touch through a glove. By two in the afternoon the water coolers on the scaffold have been refilled twice.
For most of the time people have lived on this coast, that was the end of the story. You built a house with a deep porch and a hallway that ran straight through so the breeze could pass. You slept on the screened side of the house. You did your work in the morning and again in the evening and you got through the middle of the day the way you get through a fever. The land was rich and the bay was full of fish and the summer was the price. Anybody who has stood on the pier at Bayland Park at two in the afternoon in late July has paid a small installment on that price and can imagine what the full bill was like.
Then, in the space of a couple of generations, the price was lifted, the way a crane lifts a load: it still weighs what it weighs, but something else is carrying it.
The something else is a machine that most of us have never looked at closely, though it hums outside nearly every building in Baytown. It was first built by a young engineer named Willis Carrier for a printing plant in Brooklyn in 1902. The printers did not want to be comfortable. They wanted the humidity steady so the paper would not swell and the colors would line up. Comfort came later, in theaters first, then offices, then houses, and by the middle of the last century the window unit was something a working family could buy. The Astrodome opened across the county in 1965 as the first domed stadium, and it was air-conditioned from the day it opened, and people used to say Houston was the most air-conditioned city on earth, which may or may not have been measurable but was certainly believed. The whole southern arc of the country, from the Carolinas to Arizona, filled up in those decades, and it filled up because the middle of the day had been made livable. That is what the historians mean when they say air conditioning built the Sunbelt. Baytown is a Sunbelt town twice over. It was built on oil, and it was made livable by the same energy that oil represents.
So let me be plain about what the machine does, because it is the same thing the plants on the channel do, only smaller.
An air conditioner does not make cold; there is no such thing as making cold. It moves heat from a place where you do not want it to a place where you do not care about it. Inside your house a fluid, the refrigerant, is allowed to boil at a low pressure, and boiling takes heat, so it pulls heat out of the air blowing over the coil. That vapor is then squeezed by a compressor until it is hot and dense, and pushed out to the box in the yard, where a fan blows outside air over it and the heat leaves. The refrigerant condenses back to liquid, comes back inside, and does it again. Round and round, all afternoon, without a pause.
The part that matters is the compressor. Heat does not flow from cold to hot on its own. That is one of the oldest and most stubborn laws in physics, and no engineer has ever found a way around it. You can make heat go uphill, but you must pay for every step with work. In your house that work is electricity, and in Texas the largest share of that electricity comes from natural gas burned in turbines, and much of the natural gas comes up out of the same rock and through the same pipes and past the same towns as everything else that moves through here. When you set the thermostat two degrees lower on a July afternoon, you are asking a turbine somewhere to spin a little harder. The cold in your living room is a debt paid in fire.
The plants know this better than anyone, because a refinery or a chemical plant is a heat problem before it is anything else. Nearly every process on the channel takes something apart at high temperature and then has to cool it down again. Where does that heat go? Look at the tall, open-sided towers with the white plumes rising from them. Those are cooling towers, and the plume is not smoke. It is water. Warm water from the process is sprayed down through the tower, air is pulled up through it, and a small fraction of the water evaporates, carrying the heat away exactly the way sweat carries heat off your arm. The plant sweats. What evaporates has to be replaced, so on a summer day a plant drinks water as steadily as its crews do. And on a humid afternoon it sweats less efficiently, for the same reason you do: the air coming up through the tower is already half full of water and takes less. The operators watch their cooling water temperature the way a farmer watches the sky, because every degree it climbs is a degree the whole process runs warmer than it was designed to.
An ethylene plant, the kind that stands on this channel, has to separate the gases it makes by chilling them until they turn to liquid, and some of those gases do not turn to liquid until well below a hundred degrees below zero. The plant runs cascades of refrigeration to get there, loops of propylene and ethylene doing the same boil-and-squeeze that the box in your yard does, only at temperatures that would shatter a garden hose. The coldest place in the county on a hundred-degree afternoon is inside a steel column at a plant that most people drive past without a glance. There is something fitting in that. The town that makes the fuel is also one of the biggest refrigerators you will never see.
The people who run the grid can see all of this from a control room in another part of the state, drawn as one line on one screen. The line is the load, the amount of electricity the whole of Texas is asking for at once, and on a summer afternoon it climbs from lunch until about five and peaks higher than on any other kind of day in the year. The largest single piece of that peak is air conditioning. I do not know what share of it is Baytown's, and I am not sure anybody would break it out that fine, but you can see our piece of it from the street if you know where to look: the condenser fans on the roof of the hospital on Garth Road turning without a pause, the box outside every classroom wing, the units on the back of every house on every block, all of them running at the same moment, all of them at full. Nobody hears it as noise. It is only the sound of a summer afternoon here, a low hum under everything, several thousand small compressors moving heat uphill at once, so that a child can nap and a nurse can concentrate on her patient instead of the sweat in her eyes.
The honest version of that description includes the other side: the heat you push out of your house goes somewhere, and so does the fire that paid for it. The place is livable because of the plants, and the plants are one of the reasons the afternoon is what it is. Both things sit on the same thermometer.
Toward evening the sun goes down behind Houston, and for an hour nothing changes. Then, if you are standing in a driveway on the east side, you feel it before you see it: a push of air off the water, cooler by a degree or two, smelling of salt and diesel. That is the sea breeze, and it is a heat engine as honest as any on the channel. The land heated faster than the water all day, the air over the land rose, and the air over the bay slid in underneath it to take its place. No compressor, no turbine, no bill. The oldest air conditioner on the coast, arriving on schedule, late, and welcome. The neighbor's window unit shudders and cuts off for the first time since noon. Over the fence line, a mile off, the plume from the cooling tower bends, flattens, and lies down along the wind like a flag.
