Acid reflux, commonly known as heartburn, is a condition where stomach acid flows backward into the esophagus. This causes the uncomfortable burning sensation in the chest and throat. While diet and lifestyle frequently contribute to symptom flare-ups, external environmental factors, such as high temperatures, are often overlooked triggers. The link between heat and the body’s internal response helps explain why symptoms may become more pronounced in warm weather.
The Physiological Connection Between Heat and Heartburn
When the body is exposed to extreme heat, it initiates a series of internal mechanisms to prevent overheating. The most immediate response is cutaneous vasodilation, which is the widening of blood vessels near the skin’s surface to maximize heat dissipation. This process requires the body to redirect blood flow away from internal organs, including those that make up the digestive system, in a functional trade-off to maintain core temperature stability.
This shift in blood distribution can temporarily slow down the digestive process, causing food and stomach contents to remain in the stomach for a longer duration. The delay in gastric emptying increases the volume and pressure within the stomach, which can increase the likelihood of acid being forced back through the lower esophageal sphincter (LES). Increased pressure can compromise the function of the LES, the muscular valve separating the stomach from the esophagus.
Heat stress can induce a systemic stress response, potentially contributing to the relaxation or momentary dysfunction of the LES as the body prioritizes cooling. Wearing tight clothing in the heat may also indirectly worsen the situation by physically compressing the abdomen. This compression adds to the internal pressure that pushes stomach acid upward.
Dehydration and Reduced Esophageal Clearance
The body’s efforts to cool itself through sweating lead to a significant loss of water, increasing the risk of dehydration. Dehydration directly impacts the body’s ability to neutralize stomach acid that has refluxed into the esophagus. Saliva, which is composed mostly of water, is a natural alkaline buffer that plays a major role in washing acid out of the esophagus and neutralizing its harmful effects.
When a person is dehydrated, salivary flow rates decrease, meaning less alkaline fluid is available to protect the esophageal lining. This reduction in saliva compromises “esophageal clearance,” the process by which swallowed saliva and peristalsis quickly move residual acid back down to the stomach.
Reduced fluid volume also means that stomach contents become more concentrated, making the stomach acid itself more irritating and corrosive when it refluxes. The combination of a more concentrated irritant and a reduced protective barrier contributes to the intensity of heartburn.
Managing Reflux During High Temperatures
To mitigate the worsening of reflux symptoms in hot weather, strategic hydration is important. Instead of drinking large volumes of water quickly, which can induce bloating and pressure, sip water consistently throughout the day to maintain a steady hydration level.
Sipping water consistently helps sustain a healthy salivary flow rate without overfilling the stomach. Individuals should also be mindful of beverage choices, as many popular cold drinks can exacerbate symptoms. Avoid overly cold beverages, as the sudden temperature change can sometimes trigger esophageal spasms or affect the LES. Carbonated drinks should also be limited because the gas they contain increases stomach pressure, which directly promotes acid reflux.
Focusing on lighter, smaller, and more frequent meals can prevent the stomach from becoming overly full, reducing the risk of pressure on the LES. Seeking air-conditioned environments and wearing loose-fitting clothing helps manage overall heat stress on the body. Reducing the need for the body’s cooling mechanisms minimizes the physiological trade-offs that can affect digestive function.