Extreme Heat is Rapidly Decaying Teeth in Pakistan

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Magazine : Summer 2026 : Feature

When the Heat Steals Your Smile

A dentist documents how extreme heat is turning Pakistani farmworkers’ mouths into hostile environments for their own teeth.

Photo by Florian Kopp.

Zain Azhar

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RASHID HAS CALLOUSED hands and the weathered face of a man who’s spent three decades under the Pakistani sun. What the 32-year-old doesn’t have anymore are functional teeth. Eight of them — gone in two years. The rest are deteriorating so rapidly that he’s already resigned himself to dentures by 40.

Rashid is a sugarcane farmer in Jhang District, Punjab province, where temperatures regularly exceed 45 degrees Celsius (113 degrees Fahrenheit) during peak summer months, transforming agricultural work into a form of biological endurance that few understand. Just last summer, the city of Jacobābād in Sindh province recorded 51°C — making it one of the hottest human-inhabited places on Earth and creating conditions that push human physiology to its absolute limits. When I first examined Rashid in my Lahore clinic in early 2022, I noticed something that didn’t fit the typical decay pattern I’d seen in rural patients across six years of dental practice. This wasn’t the gradual erosion from poor hygiene or untreated cavities that you’d expect in communities with limited access to healthcare. This was aggressive, systematic dissolution — as if teeth were being chemically attacked from the inside out, dissolved by forces entirely beyond individual control or comprehension.

This was environmental collapse writing itself directly into human biological systems.

Like most outdoor laborers during peak season, Rashid drinks 15 to 20 liters of water daily to survive the relentless heat. (While this can seem like an excessive amount of water, a worker can sweat as much as 1 to 1.5 liters an hour from heavy labor in 45°C temperatures. To compensate for the loss of electrolytes through sweat, workers here consume yogurt and lime drinks with added salt, and eat pickles and other salty foods.) By mid-morning, sweat soaks through his clothes as his body’s cooling mechanism works overtime. He chews on sugarcane during breaks, which provides quick calories — an ancient practice that sustained ancestors but now compounds health problems. Nothing about his general health seemed unusual at first. But when I asked about saliva — that often-overlooked component of oral health that most people never think about — there was a long pause.

“My mouth is always dry,” he said quietly in Urdu. “Even when I drink water until I feel sick. My mouth stays dry.”

That’s when something clicked into place that would fundamentally reshape my understanding of what I’d been observing in my practice. I’d documented this pattern of tooth decay in 37 patients by this point, all agricultural workers, all from the same climate-ravaged zones in the central-eastern state of Punjab. I just hadn’t connected the dots to heat-induced dehydration and its catastrophic effects on oral chemistry. Their mouths weren’t just dry — external climate forces were fundamentally turning them into hostile environments for their own teeth. I realized I was witnessing something far more systemic and urgent than a collection of individual dental problems. This was environmental collapse writing itself directly into human biological systems.

SALIVA IS NOT just moisture. It’s a physiological fortress, a sophisticated system that most people take entirely for granted until it fails them. For anyone, but especially for people doing physically demanding work in extreme conditions, saliva performs three critical functions that are absolutely essential to tooth survival: It buffers acids from food and stomach reflux that would otherwise erode enamel; it holds calcium and phosphate minerals, which actively remineralize tooth enamel when microscopic damage occurs; and it contains enzymes and antibodies that fight bacteria, helping prevent infection and decay. Without adequate saliva flow — and I mean genuinely adequate, not just the minimal amount needed to swallow — teeth begin to demineralize within weeks, a process that becomes increasingly difficult to reverse.

In Pakistan’s Punjab province, temperatures regularly exceed 45°C (113°F) during peak summer months, transforming outdoor labor, like brick work, “into a form of biological endurance that few understand.” Photo by Adam Cohen.

A day laborer in Islamabad, Pakistan, pauses from his work of harvesting wheat by hand using a sickle, known locally as a daranti. During extreme heat, agricultural work can push the human body to its limits. Photo by A. Yaqub / CIMMYT.

Heat stress triggers a biological cascade that is as predictable as it is brutal....