This city roars in the summertime. You hear the generators on every street, shaking and shuddering to keep electric fans whirring as the air seems to shimmer in the heat.

Iraq isn’t just hot. It’s punishingly hot. Record-breakingly hot. When one of us returned here last week, the air outside felt like an oven. The suitcase crackled as it was unzipped. It turned out that the synthetic fibers of a headscarf had melted crispy and were now stuck to the top of the case. A cold bottle of water was suddenly warm to the lips. At our office, the door handle was so hot it left blisters at the touch.

Baghdad hit 125.2 degrees on July 28, blowing past the previous record of 123.8 degrees — which was set here five years ago — and topping 120 degrees for four days in a row. Sitting in one of the fastest warming parts of the globe, the city offers a troubling snapshot of the future that climate change might one day bring other parts of the world.

Experts say temperature records like the one seen in Baghdad will continue to fall as climate change advances.

"It’s getting hotter every year," said Jos Lelieveld, an expert on the climate of the Middle East and Mediterranean at the Max Planck Institute in Germany. "And when you are starting to get above 50 degrees Celsius (122 degrees Fahrenheit) it becomes life threatening."

The air temperature forced almost everyone indoors. Those who were still out on the streets tried to make a living selling cold drinks or fruit that festered in the heat. We saw them crouching in shade from a beating sun that offered few shadows, plunging their hands and faces into ice boxes which had long since melted.

We asked a traffic cop if there was anything he could do to stay cool. He shook his head. "There’s nothing."

If the world acts to dramatically limit climate change, such extremes of heat, with temperatures above 120 degrees, would probably be limited to parts of the Middle East, Northern Africa, and India, Lelieveld said.

But if not, temperatures in parts of the Persian Gulf region and South Asia could eventually exceed 130 degrees. Nor would the rest of the world be spared extreme spikes. Indeed, one recent study found that by the year 2050, the climate of Phoenix could closely resemble that of Baghdad.

Some countries are better equipped to cope than others. But Iraq’s infrastructure was decimated by sanctions before the 2003 U.S. invasion and then years of conflict and corruption that followed.

The heat is ruining livelihoods, and power cuts have been compounding a sense of misery so deep that protesters are streaming into the streets to demand better services, even risking the threat of live ammunition from ill-disciplined security forces. At least three protesters have been killed since last month. No one believes they will be the last.

The heat is straining a power grid that was already on its knees. Those who can afford it rely on exorbitantly priced private generators to power a few lights and a fan. Those who cannot just swelter, exhausted in the dark.

Last year, Philip Alston, the United Nations Special Rapporteur on extreme poverty and human rights, warned of a coming "climate apartheid" scenario. This is what it starts to look like.

Many foreigners in Iraq are lucky. The Washington Post’s Baghdad bureau has a generator and near constant power supply, putting us in a tiny minority, along with the politicians and executives sequestered in compounds with guards at the door. But for many households, a generator to keep the lights and perhaps a television on will cost about half of the monthly income.

In southern Iraq, the heat and lack of rainfall are contributing to a water crisis that has forced tens of thousands of people to leave their homes over the past decade. In July, a report by the International Organization for Migration warned there is a high chance this will continue.

Warming in the country is far above average. Data from Berkeley Earth show that, compared with the country’s temperature at the close of the 19th century (1880-1899), the last five years were 2.3 degrees Celsius, or 4.1 degrees Fahrenheit, hotter. The Earth as a whole has only warmed by about half that amount over the same time period.

Farmers whose families have worked the land for generations say they are losing crops and their incomes are plunging. In the eastern district of Al-Adhamiyah this week, 47-year-old Moatez Ghalib surveyed the grove of plants he was trying to sell for homes and balconies. Leaves curled yellow. Some were so brittle you could snap them.

He looked down at his feet. "It’s all burning," he said sadly. "The heat here is changing our lives."

When you talk to Iraqis about the rising heat in Baghdad, the city’s disappearing green belt comes up time and again. Palm trees were beheaded by American and Iraqi forces, in an attempt to stop militants hiding there during the civil war. Where there once were miles of farmland, property has been expropriated and sold to the highest bidder. The squat brown-brick sprawl of informal settlements is also spreading.

Such changes in the landscape have probably exacerbated what scientists call the "urban heat island effect," in which cities tend to register higher temperatures than the surrounding landscape because buildings and pavement often gather heat, rather than reflecting it back toward space.

Ghalib’s family has worked two of the remaining farms for three generations. His grandfather passed the family farm onto Ghalib’s father, and now the 47-year-old is in charge of it too. As a schoolboy, he watered the fields daily. "Being here in the green land, it relaxed me. I’d stay here for hours before going home to finish my homework," he said. "We can’t have that life anymore. It’s too hot."

One of his day laborers was out for 10 days last week with sunstroke, and the farm couldn’t pay him as he convalesced. "The sun burned his bones," Ghalib said. "Our bodies can’t take it, we just can’t work like we used to." He is coming to terms with the fact his children will not take over the farm, a prospect that he says would have stricken his late father.

A desert country like Iraq is warming more rapidly, explained MIT climate expert Elfatih Eltahir, because it is so dry. While additional heat in many places would partially go toward evaporating moisture in the soil, there just isn’t much such moisture in Iraq.

"This is the region where there is no moisture," Eltahir said. "So any added greenhouse effect, it has to go into sensible heat."

If there’s some sliver of good news, it is that at least in Baghdad, which is relatively distant from the Persian Gulf, an extremely high heat event like this one is less likely to also feature high levels of atmospheric humidity.

Combinations of high heat and humidity, Eltahir has found, can lead to literally lethal outdoor temperatures because humans are unable to cool down their bodies through sweating. And his research projects that these conditions will start to occur in some parts of the Middle East as warming continues.

While Iraq has seen its temperatures rise usually fast, the rest of the world is projected to see similar increases in the decades ahead. Extreme warming is coming everywhere.

As the tangerine-colored sun slipped below the Baghdad skyline Thursday, a construction worker looked up, shook his head, and then stretched out his arms as if he was hugging the sky.

"Thank God," he shouted at another laborer, nodding up at where the sun once hung. "Our friend has gone to bed."