When a person swallows food or liquid that is too hot, the immediate result is a thermal injury to the mucous membranes of the upper digestive tract. The severity of the resulting burn depends on several factors, including the substance’s temperature, the duration of contact with the tissue, and the volume swallowed. Soft tissue can sustain damage when exposed to temperatures significantly above 140°F (60°C).
Immediate Damage to the Mouth and Throat
The initial contact points for hot food are the lips, tongue, and the lining of the mouth, which are highly sensitive. The acute effects of heat exposure manifest as immediate pain, redness, and inflammation of the oral mucosa. As the heat causes cellular damage, the tissue may develop blisters, and the top layer of the mucous membrane can begin to peel away.
If the hot substance progresses past the oral cavity, the pharynx and surrounding structures, including the tonsils and the back of the throat, become affected. This damage often leads to painful swallowing (odynophagia) and difficulty swallowing (dysphagia). A more concerning acute consequence is thermal injury to the larynx, or voice box, which can cause swelling of the airway structures.
Laryngeal swelling may present as a change in voice quality, such as hoarseness, and in severe cases, can progress to airway obstruction. The rapid onset of swelling in this region can be life-threatening and may occur even if the external signs of a burn in the mouth are minimal.
Thermal Injury to the Esophagus and Stomach Lining
If the excessively hot food or liquid bypasses the protective reflexes of the mouth and throat, the primary site of serious injury becomes the esophagus. The esophageal lining is particularly susceptible to thermal damage, which can range from superficial inflammation (esophagitis) to deep ulcerations. The severity of the burn depends heavily on the duration of contact, meaning thick, hot solid food tends to cause more localized, deep burns compared to hot liquids, which cause more diffuse injury.
Endoscopic examination of the esophagus after a burn often reveals signs of injury, such as linear erythema (redness) and the formation of whitish pseudomembranes where the superficial tissue has died. In some cases following liquid ingestion, this pattern can create a unique finding known as “candy-cane” esophagus. Deeper burns can lead to full-thickness tissue death, which carries a risk of esophageal perforation, a medical emergency where a hole forms in the esophageal wall.
The stomach lining is generally more resilient to thermal injury than the esophagus due to the protective layer of mucus and stomach acid. However, if an extremely hot bolus of food is swallowed quickly, damage is possible, though less common than esophageal injury. When stomach injury does occur, it can present as gastritis, or inflammation of the stomach lining, or in rare, severe instances, ulceration. Symptoms of internal injury usually include persistent chest pain, which is often mistaken for heartburn, and discomfort that continues long after the initial burning sensation.
Urgent First Aid and When to Seek Medical Help
Immediate action following the ingestion of very hot food should focus on rapidly cooling the affected tissues and minimizing further irritation. The first step is to quickly sip and swish cool liquids, such as cold water or milk, to lower the temperature of the oral and pharyngeal mucosa. Avoid consuming acidic, spicy, or abrasive foods for several days, as these can irritate the newly damaged tissue and slow the healing process.
Over-the-counter pain relievers can help manage the discomfort, and sucking on ice chips or throat lozenges may provide a continuous soothing effect to the throat. People should also avoid gargling with harsh mouthwashes or very hot or cold liquids, which can further shock the injured cells. The majority of mild thermal injuries to the mouth and throat will heal on their own within a few days of conservative care.
However, certain signs require an immediate trip to the emergency room, as they indicate a potentially severe internal burn or airway compromise. These “red flags” include:
- Difficulty breathing.
- A significant change in voice quality.
- Stridor, a high-pitched, wheezing sound while inhaling.
- The inability to swallow even small amounts of liquids (aphagia).
- Persistent severe chest pain or vomiting blood, which suggests significant internal ulceration or perforation.
Long-Term Health Concerns and Prevention
While most superficial thermal injuries heal completely, a severe or repeated thermal insult to the esophagus can lead to chronic health issues. A primary long-term complication is the formation of esophageal strictures, which are areas of scarring that cause the esophagus to narrow. This narrowing can cause long-term dysphagia, requiring endoscopic dilation procedures to stretch the scarred tissue and restore normal swallowing function.
Repeated exposure to high-temperature foods and liquids over many years is also associated with an increased, though rare, risk of developing esophageal cancer. The chronic thermal trauma and subsequent cycles of cell damage and repair are thought to promote pre-cancerous cellular changes in the esophageal lining. To prevent this type of injury, always check the temperature of food and beverages before taking a large bite or swallow. Waiting a few minutes for steaming items to cool, or stirring food with a utensil to allow heat to dissipate, can significantly reduce the risk of accidental thermal burn.