Growing Threat to Heat-Exposed Workers: Chronic Kidney Disease

Two years ago, Ignacio, a construction worker in Houston, began having frequent headaches and fatigue. Then 40, he initially didn’t go to a doctor because he was uninsured. His wife found a clinic that would see him for free.

He was diagnosed with high blood pressure and high cholesterol and sent home. A few hours later, someone from the clinic called, asking Ignacio to return immediately. When he failed to show up, the clinic employee called again. He needed to go to urgent care because his heart could fail while he was asleep, they told him.

Ignacio, who is undocumented and asked that his last name not be used, was diagnosed with Stage 5 kidney disease and now undergoes dialysis three times a week, for four hours at a time.

An underappreciated threat—heat—may be at the root of Ignacio’s condition. Indeed, some researchers have called chronic kidney disease the first chronic illness directly linked to climate change. While no clinical test exists to determine the precise cause of the ailment known as CKD, a growing body of evidence shows that working in hot weather slowly damages the kidneys. Ignacio has worked in construction in Texas, one of the hottest states, for more than 10 years.

CKD has upended Ignacio’s life and mental health. At first, he thought he was going to die and worried what his family would do without him; his youngest daughter was four when he was diagnosed. He used to work 70 to 80 hours a week, but now can work only 40.

“It’s like now I only have half of my life,” Ignacio said. “Your life now depends on this [dialysis] machine.”

Researchers are still unraveling all the ways extreme heat affects the human body. Early in this century, researchers in warmer parts of the world—Central America, South Asia—began noticing a spike in kidney disease among younger, otherwise healthy people. Many looked like Ignacio: they hadn’t previously been diagnosed with diabetes or hypertension and their occupations exposed them to heat day in and out.

Although they acknowledge the surge in CKD could have multiple causes, health experts nevertheless have concluded that there is a common denominator: hotter temperatures.

A diagnosis of Stage 4 or Stage 5 kidney disease can lower a person’s life expectancy by 15 to 20 years, condemn them to lifelong dialysis and disrupt their immune, endocrine and circulatory systems. Nearly one out of four or five chronic kidney disease patients experiences a major depressive disorder. Mental health problems are so common among dialysis users that Medicare guidelines require patients to be screened for depression after 90 days in treatment and then at least once a year. In June, a review paper found that the suicide rate among dialysis patients is at least double the rate of the general population.

Cover photo:  A construction worker ushers traffic on July 11, 2023, during a record-setting heat wave in Austin, Texas. Credit: Brandon Bell/Getty Images