Doctor shares tips to protect kidney function during extreme heat

Dr. Ngo Van Tan of the HCMC University Medical Center highlights a growing public health concern: the surge in extreme heatwaves, with temperatures frequently surpassing 38°C, is placing unprecedented strain on the human renal system. While many people believe that simply increasing water intake is a universal fix for heat-related stress, the reality is far more nuanced. The kidneys serve as the body's sophisticated filtration and balancing hub, and when the body loses excessive fluids through perspiration without precise replenishment, the consequences can be severe even for individuals with no history of medical issues.

The primary danger during these high-temperature periods is the crystallization of minerals within the urinary tract. As the body becomes dehydrated, urine concentration spikes, allowing substances like calcium, uric acid, and oxalate to solidify into kidney stones. This biological process explains the seasonal uptick in stone-related hospitalizations during the summer. Beyond the risk of stones, the expert warns that improper hydration techniques—such as "chugging" massive quantities of water all at once after being in the sun—can be counterproductive. This habit can trigger a rapid dilution of blood sodium, leading to dangerous electrolyte imbalances characterized by dizziness, headaches, and profound fatigue.

Furthermore, the type of fluid consumed is just as critical as the volume. Dr. Tan cautions against the overconsumption of sugary soft drinks and energy beverages, which are often marketed as thirst-quenchers but actually increase metabolic pressure and accelerate the formation of kidney stones. Instead, the recommendation is to sip plain water consistently throughout the day, even in the absence of thirst. For those performing heavy manual labor, moderate electrolyte supplementation may be necessary, but for the average person, plain water remains the gold standard for maintaining a stable internal environment.

From a lifestyle perspective, the heat dictates a change in how we treat our bodies after exertion. One common mistake is taking a cold shower immediately after being exposed to intense heat or finishing a workout; such sudden temperature shifts can shock the system and disrupt metabolic harmony. Traditional medicine views summer as a "fire" element that actively depletes the body’s essential fluids, suggesting that a diet rich in cooling fruits and vegetables is necessary to provide a secondary source of hydration and temperature regulation.

To prevent long-term damage, individuals must become vigilant about the subtle warning signs of kidney distress. Indicators such as reduced urine output, unusually dark or strong-smelling urine, and a persistent dull ache in the lower back or flank should not be ignored. By adopting a proactive approach—drinking in small, frequent intervals, avoiding sugary stimulants, and monitoring physical changes—people can navigate extreme weather conditions without compromising their long-term metabolic and renal health.