In her tin-roofed home in Basra, a few hundred feet from the great churn of the Shatt al-Arab River, Shamaa Mustafa blinked as a bead of sweat ran into her eye. On the floor sat her children, shining with perspiration, hair sticking up in tufts, mouths hanging open.

It was 125F and, for the fifteenth day in a row, the electricity had cut out. They could do nothing to escape the heat pressing down on them like a steam iron in the Iraqi city.

The water that came out of the tap was hot. The ground they lay down on to rest was hot. The walls were hot, the roof was hot. They couldn’t sleep, short of a few snatched hours when the air was at its coolest. Going out meant risking sunstroke. The children couldn’t go to school, where — with 40 students crammed into a room — it was even hotter than at home.

Two hours’ drive to the south, in Kuwait City, another family was sitting down to an early dinner. Outside, it was the same temperature as in Basra, heat shimmering over the desert highways. But inside, the air-conditioning made it so cold that a shivering guest had to wrap themselves in a blanket.

Life on the inside: in Kuwait City, a woman stares at the Kuwait Towers.

They had been to the mall earlier that day, taking their exercise along cooled glass-fronted avenues. The only time they had stepped outside was to get in and out of the air-conditioned car.

The cities are just 80 miles apart, on the northern edge of the Persian Gulf. They are both among the hottest inhabited places on Earth and sit on a lake of oil so absurdly plentiful that — in Basra, at least — it has been known to trickle down the streets.

But in Kuwait, there is a constant supply of electricity. Kuwaitis swim in pools cooled down to 64F and, in the evening, walk in parks in a mist of chilled water droplets sprayed from cooling systems above them. Even the poorest Kuwaitis have air-conditioning in their cars and homes (though many of the millions of migrant workers, who account for nearly two-thirds of Kuwait’s population, suffer in the heat despite legislation designed to stop them working during the hottest parts of the day).

Farm animals drink chilled water. Chicken coops are air-conditioned to a comfortable 71F. Stables and riding schools are chilly.

In Basra, the relentless heat brings suffering that doesn’t let up at night, where temperatures can stay in the low-100s. Children cry, tired parents get angry. Farm animals die. Rivers dry up and water turns green and rank.

This is the future of climate change: a terrifying dystopia where the rich survive, stepping between their islands of air-conditioning, and the poor suffer in the heat, or are forced to flee.

After a week where temperatures in Britain hit 104F for the first time, it is a future that many people living in what were once cool areas are beginning to imagine — and to fear.

In Basra, the relentless heat brings suffering that doesn’t let up at night, where temperatures can stay in the low-100s. Children cry, tired parents get angry. Farm animals die. Rivers dry up and water turns green and rank.

For the people of Kuwait and Basra, this dystopia isn’t an abstract idea but an encroaching reality. It can be counted in the dying palm trees, the bath-warm water and the pounding, relentless sun that seems to grow hotter every year.

“Of course, without air-conditioning you couldn’t live here,” laughed Adel al-Yahya, a Kuwaiti lawyer, as he sat on a bench inside a frigidly conditioned mall. “It would be impossible.”

Outside, in Basra and Kuwait, the heat is everywhere, like soup in your mouth or stinging fire in your throat — depending on the humidity. At its worst, you hold your tongue to the back of your front teeth because it hurts to breathe in the air directly. Your eyes prickle, their surfaces drying.

Life on the outside: Iraqi youth swim in the Shatt al-Arab River amid a heatwave in Basra.

It didn’t used to be like this. This part of southern Mesopotamia, where the Tigris and Euphrates rivers flow into the Persian Gulf, was once so fertile that scholars have suggested it could have been the location of the biblical Garden of Eden.

Even ten years ago, everyone we spoke to in both cities agreed, summers were perfectly survivable. Children could play outside, and families could picnic by the water, in the shade of the palm trees; by October, they’d be putting on jumpers. In Basra and Kuwait alike, people remember when what is now desert was green. Plants used to grow: shrubs, trees, date palms. Even tomatoes, if they were planted in the shade.

“You didn’t used to be able to drive out there,” said Shabib al-Ajmy, a farmer and businessman in his mid-forties who advises the Kuwaiti ministry of agriculture, gesturing at the rolling desert behind his house. “It was all green, all plants. And that kept the air cool.”

When he was a child, he said, he had played outside, herding sheep under the trees.

Now his ten-year-old son spends much of his time in the house, drinking Pepsi and playing on his phone. The only other place he can go is the family’s air-conditioned greenhouse, where al-Ajmy grows bananas and figs, and which feels pleasantly cool at 86F.

On the land in front of al-Ajmy’s house, he has planted desert shrubs and trailing plants in an attempt to capture some of the life that used to be there. Already rabbits, birds and lizards have burrowed in under the shade of the leaves. For now, at least, he is fighting a losing battle. Around the plot of green stretches a vast, rubbish-strewn desert littered with power lines and the odd dead camel.

It is one of the hottest places in the world. In 2016, a desert spot in Mitribah, Kuwait, less than 40 miles from the capital, measured 129F. The only higher temperatures recorded anywhere have been in remote parts of California and Tunisia.

Over the past 60 years, said Hassan al-Dashti, climatology superintendent at the Kuwait Meteorological Department, temperatures in Kuwait have increased by 3 degrees Fahrenheit, significantly higher than the global average.

The extremes between the high and low temperatures, particularly in summer, have increased still more significantly.

“This has an effect on many things, in the evaporation, in the land, in the ocean, in the species of the sea, in the planting, everything, in the health of the people suffering from the high temperature,” said al-Dashti. “Admission in hospitals has increased due to high temperatures. Your social activity will change … the feedback and impact is too much.”

Living the lives that his grandparents’ generation had in Kuwait — without electricity, based in tents or small houses — would, with the rising temperatures, be impossible today, he said.

Kuwait’s Environmental Protection Agency, in an e-mailed statement, said that the rise in temperatures was global and not something specific to Kuwait, adding that the government had made efforts to counter them.

The Iraqi government has said it is trying to address the electricity crisis and combat the effects of climate change and environmental damage.

Many Iraqis have given up trying to work the land.

Ramshackle settlements have sprung up everywhere in Basra as farmers and villagers move into the city, further burdening the infrastructure and increasing poverty levels.

The rising temperatures in Iraq are, scientists say, partly down to global climate change. Yet they are exacerbated by local circumstances and a lack of good governance and infrastructure.

Oil companies have been allowed to massively expand their operations around Basra, eating up farmland. Pollution and long-running disputes with Turkey and Iran over the water supply have increased the salinity of the Shatt al-Arab, killing plants and animals, and helped dry up the nearby marshes.

Iraq, once known as the “country of 30 million palm trees,” has seen decades of conflict and environmental challenges, including drought, desertification, and salinization, which leave many of them dead or damaged.

All of this has combined to the rising temperatures. Still, with a strong supply of electricity and clean water, life would be just about tolerable. Instead, there have been years of incessant cuts to both. Locals blame corruption in the Iraqi government.

“Under Saddam, there was one thief. Now there are thieves everywhere,” said Ahmed Hameed Aziz, 42, whose home receives only a few hours of electricity a day, none of it strong enough to power an air conditioner.

Fury with the deterioration of public services has boiled over several times over the past years in Basra, stoking protests and demonstrations, some of which turned deadly when security services opened fire.

The future looks bleak. In his office in the city, Falah Hassan Alamiri, an activist and researcher who wrote his PhD on Iraq’s electricity supply, said Basra was quickly becoming uninhabitable.

“In ten years it’ll be a city of factories and oil companies,” he said. “People won’t live here.”

Earlier last month, after a day so hot that it hurt to breathe, Basrawis started to trickle down to the river’s edge, buying ice cream and looking out over the water.

A group of teenage boys were wading around in the shallows on the bank of the Shatt al-Arab, splashing one another with the gray-tinged water, watermelon rinds and dead fish floating at their feet.

“There’s no electricity at home, it’s too hot to be there,” said Hussein, 18, laughing as he aimed a kick at one of his friends. “At least in the water it’s cold.”

Louise Callaghan is the multi-award-winning Middle East correspondent for The Sunday Times. She lives in Istanbul and reports from Turkey, Syria, Iraq, and Saudi Arabia