Repeated exposure is a different concern. The IARC reviewed research from populations where people traditionally drink tea or other beverages at very high temperatures. Studies found an association between very hot beverage consumption and increased esophageal cancer risk. The temperature appeared to be more important than whether the drink was tea, coffee, or another beverage.
This helps explain why the warning is not limited to boiling water. Very hot tea, coffee, herbal drinks, and other liquids can also create a thermal exposure problem.
Why the 65°C threshold matters
The IARC uses a temperature above 65°C to define very hot beverages in its evaluation.
This figure is a scientific classification threshold, not a guarantee that every drink below it is completely risk-free or that every drink above it will cause injury.
The practical message is straightforward: do not drink a beverage while it is still scalding hot. Allow it to cool until it can be comfortably swallowed without burning the mouth or throat.
There is no need to measure every cup with a thermometer. Waiting for the liquid to cool naturally is a sensible everyday precaution.
Does the body repair heat damage?
The lining of the esophagus has mechanisms that help maintain and repair its surface. However, repeated injury can create ongoing inflammation and tissue repair.
Scientists believe that chronic thermal damage may contribute to the development of cancer in some circumstances. The exact biological pathway and the level of risk for an individual person are not fully predictable.
Importantly, this does not mean that a person who once swallowed a very hot drink has developed cancer. Nor does it mean that temporary throat discomfort is evidence of a tumor.
Cancer develops through complex changes in cells over time. Temperature is only one factor associated with esophageal cancer risk.
Which other factors matter?
Smoking and alcohol are major risk factors for esophageal cancer, particularly for certain types of the disease. Other factors can include obesity, chronic acid reflux, and specific medical conditions.
The relative importance of these factors differs according to the type of esophageal cancer and the population being studied.
A warm drink can be enjoyed more comfortably after it has cooled to a safe temperature.
Should you stop drinking warm water?
No. Warm water is not inherently harmful. Many people prefer it because it feels comfortable, especially in the morning or during cold weather.
The concern is excessive heat, not warmth itself. Water that has been boiled and allowed to cool is different from water swallowed directly from a vigorously boiling kettle.
A sensible routine is to boil water when needed, pour it into a suitable heat-resistant container, and wait until it is comfortably warm or cool before drinking.
If swallowing causes persistent pain, difficulty, or a sensation that food is getting stuck, seek medical advice rather than assuming that it is simply irritation from a hot drink.
Repeated difficulty swallowing is a symptom that deserves assessment, particularly if it is getting worse or is accompanied by unexplained weight loss.
The goal is not to create fear around everyday drinks. It is to understand how repeated exposure to extreme temperatures may affect delicate tissues and to make a simple change that reduces avoidable risk.
Chapter 3: Stomach Cancer Has Different Causes—And Hot Water Is Not an Established One
The headline in the supplied image specifically mentions stomach cancer. This makes it important to examine what medical research actually says about the disease.
Stomach cancer develops when cells in the stomach begin growing abnormally and form a tumor. It can affect different parts of the stomach and may progress without producing obvious symptoms in its early stages.
Unlike the evidence concerning very hot beverages and esophageal cancer, there is no established medical evidence that drinking properly prepared boiled water causes stomach cancer.
Researchers have identified several risk factors that are much more relevant.
1. Helicobacter pylori infection
One of the most important risk factors for stomach cancer is long-term infection with a bacterium called Helicobacter pylori, commonly known as H. pylori.
This bacterium can live in the stomach lining and cause chronic inflammation. In some people, prolonged infection leads to changes in the stomach tissue, including atrophic gastritis and intestinal metaplasia. Over time, these changes can increase the risk of developing stomach cancer.
Many people infected with H. pylori never develop cancer. Nevertheless, identifying and treating the infection when appropriate can reduce future risk.
The US National Cancer Institute identifies chronic H. pylori infection as a major risk factor for stomach cancer. It also reports that studies have found a reduction in stomach cancer incidence following successful eradication treatment in certain populations.
2. Eating large amounts of salty and preserved foods
Diet can also influence stomach cancer risk.