by Sanket Jain, Yale Climate Connections
July 1, 2026
Sharp abdominal pain stabbed at Suvarna Dange after she spent a long day in April 2026 working the sugarcane fields in India in extreme heat over 39 degrees Celsius (102.2 F). Four hours later, the pain was unbearable, and the 50-year-old vomited after returning to her cement home in Kolhapur district. She had to wait until morning to see a doctor, when a scan revealed a kidney stone.
The doctor told her that a long workday in the heat with few rest breaks and insufficient water probably played a role in the stone, a hard deposit formed from crystallized minerals and salts in the urine. He prescribed medication and asked her to drink more water. But her job did not provide time off, and she returned to work the same day.
“No matter how hot it gets, we keep working,” she said.
She labors in the fields from 10 a.m. to 6 p.m., with just a short break and few opportunities to drink water. In her village, summer temperatures frequently rise above 39 degrees Celsius.
Climate change has made dehydration a more serious health risk around the world. About half the people in the world are suffering the consequences of more frequent and more intense extreme heat events, according to a 2025 report by the World Health Organization and the World Meteorological Organization. The report said worker productivity drops by 2-3% for every degree above 20 C (68F). Health risks include heat stroke, dehydration, kidney dysfunction, and neurological disorders.
Experts say the risks are often elevated for women, who may drink less water because they have little or limited access to toilets during work hours. And after work, many women return home to cook, clean, and care for children and family members, often in hot and poorly ventilated spaces.
“As extreme heat events become more frequent and severe, we expect the prevalence of dehydration, heat-related illness, and kidney injury to rise,” said Behdin Nowrouzi-Kia, an occupational therapist and assistant professor at the University of Toronto in Canada.
Among sugarcane workers in Guatemala, heat exposure and dehydration during workdays were closely linked to kidney injury, according to a 2025 study published in the Journal of Climate Change and Health. Nearly half the workers showed signs of reduced kidney function.
“In heat stress, particularly during heavy physical labor, blood is redirected toward the skin to dissipate heat, which reduces blood flow to internal organs such as the kidneys,” explained Jaime Butler-Dawson, an epidemiologist and an adjunct assistant professor at the Colorado School of Public Health, who led that study. Dehydration, she noted, amplifies this effect by lowering the amount of blood circulating in the body. This means the kidneys may not get enough oxygen, and the structures that filter waste become stressed, raising the risk of acute kidney injury.
Her team saw signs of kidney strain even across a single work shift. Workers who became dehydrated during intense labor showed reduced kidney function, and some developed acute kidney injury.
“These effects occur even when dehydration is relatively mild, indicating that heat strain is a critical driver of kidney injury,” she said.
The damage appeared to build through many small, repeated stresses each hot workday. With incomplete overnight recovery, this gradual strain can contribute to long-term kidney dysfunction.
The World Health Organization and World Meteorological Organization report recommended that governments, employers, and local and regional health authorities develop occupational heat-health policies. Plans and advisories should be tailored to local weather conditions and focus on vulnerable populations such as middle-aged and older workers, individuals with chronic health conditions and other fitness or health problems, the report said. The report also called for technical innovations and support for further research on better protecting workers worldwide.
How dehydration strains the body
When fluid loss is not fully replaced, the body conserves water, producing smaller amounts of urine more concentrated with substances such as calcium and oxalate. This makes it more likely that crystals can form and grow into kidney stones.
A month after Dange’s kidney stone diagnosis, the pain returned, this time more severe. The doctor asked her to avoid working in extreme heat.
“I am taking medicines again,” she said, adding that she does not know how long she can keep working.
Researchers who studied more than 1,400 Indian outdoor workers found they were 2.5 times more likely to experience high heat stress under humid conditions. A review of 17 studies led by Nowrouzi-Kia, conducted largely in North and Central America and Asia, found that heat exposure impairs construction workers’ physical health, particularly through dehydration and heat-related illness.
Beyond the kidneys
Dehydration can also strain the cardiovascular system. As the body loses fluids, the blood becomes more concentrated, and clots are more likely to form. Electrolytes can fall out of balance, disrupting the electrical signals that regulate the heartbeat, risking arrhythmia. The heart also must work harder to keep blood circulating. Dehydration raises the risk of heart attack or stroke for people with underlying cardiovascular conditions, experts say.
As fluids are lost through sweat, the body also loses sodium and potassium, disrupting nerve signals and muscle function. It can disrupt how muscles contract, leading to cramps, weakness, and reduced physical capacity.
Indian farmworker Chingu Yadav, 53, grew restless one evening, and the next morning she was admitted to a hospital. Doctors told her persistent dehydration had affected her kidneys and heart. She quit farm work after a similar episode the following year, but the damage was done. Yadav says she now feels constantly weak and struggles with routine tasks. She worries about losing her balance when she walks. Her doctor told her such symptoms can also be linked to the body’s loss of essential electrolytes during prolonged dehydration.
She has since started carrying water whenever she steps out and tries to rest as much as possible. For more than three decades, she had worked up to 10 hours a day in the fields.
“I never paid attention to how dehydration was affecting my health all these years,” she said. “Earlier, I could work the entire day and not feel this tired,” she added. “Now, even an hour in the heat feels scary.”
Butler-Dawson said women’s experience of heat is shaped by both biology and working conditions. Even when doing similar or less physically intense work, women may experience heat strain differently.
“Physiologically, women may differ from men in sweating rates, body composition, total body water, and hormonal regulation, all of which influence thermoregulation and heat dissipation,” she said.
When hydration isn’t enough
Researchers tracking Latino farmworkers in North Carolina found dehydration worsening dramatically over the course of the workday. Before work, nearly half the workers showed signs of dehydration. By the end of the day, all of them did. Limited access to clean drinking water, few breaks, and harsh working conditions made it difficult for workers to stay hydrated.
“Improved access to drinking water and scheduled rest breaks are foundational,” Nowrouzi-Kia said.
Regular fluid intake, he said, helps workers stay productive even in extreme heat. Protecting workers from extreme heat includes training workers to recognize early signs of heat-related illness and putting heat alert programs in place.
Butler-Dawson said that the most effective strategies combine regular rest breaks with access to shade or other cooling strategies to help the body recover, along with replacing fluids and salts lost through sweat.
“Protecting health with increasing and more frequent extreme temperatures requires redesigning work policies and practices to match new environmental realities, rather than asking bodies to endure unsafe conditions,” she added.
Back in Kolhapur, Dange continues to work in the fields even during the heat waves. She now takes breaks when she can and tries to stay hydrated.
“People think they are used to working in the heat,” she said. “But heat spares no one.”
This <a target=”_blank” href=”https://yaleclimateconnections.org/2026/07/stabbing-pain-sent-her-to-the-doctor-the-underlying-cause-is-getting-more-common-everywhere/”>article</a> first appeared on <a target=”_blank” href=”https://yaleclimateconnections.org”>Yale Climate Connections</a> and is republished here under a <a target=”_blank” href=”https://creativecommons.org/licenses/by-nc-nd/4.0/”>Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License</a>.<img src=”https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2020/10/ycc-favicon.png?resize=100%2C100&ssl=1″ style=”width:1em;height:1em;margin-left:10px;”>
<img id=”republication-tracker-tool-source” src=”https://yaleclimateconnections.org/?republication-pixel=true&post=139846&ga4=1401ERFF5Q” style=”width:1px;height:1px;”><script> PARSELY = { autotrack: false, onload: function() { PARSELY.beacon.trackPageView({ url: “https://yaleclimateconnections.org/2026/07/stabbing-pain-sent-her-to-the-doctor-the-underlying-cause-is-getting-more-common-everywhere/”, urlref: window.location.href }); } } </script> <script id=”parsely-cfg” src=”//cdn.parsely.com/keys/yaleclimateconnections.org/p.js”></script>
