The focus on hot drinks often centers on what is in the cup, such as caffeine or sugar levels, but a significant health consideration is the sheer heat of the beverage itself. The temperature at which a liquid is consumed presents distinct risks, ranging from immediate physical trauma to long-term cellular damage. Exploring the thermal aspect alone clarifies why certain consumption habits can pose a danger to the sensitive tissues of the mouth and throat. The health concerns associated with hot beverages are directly related to the degree of heat, not the chemical properties of the drink.
The Immediate Danger of Scalding
The most immediate danger of a hot drink is the risk of scalding, which can cause painful first- and second-degree burns. Many establishments serve beverages between 160°F and 180°F (71°C to 82°C), far above the threshold for rapid injury. These high temperatures can inflict serious thermal injury almost instantaneously upon contact with the delicate mucosal lining of the mouth, tongue, and throat. Burn severity is determined by both the liquid’s temperature and the duration of exposure.
Exposure to a liquid at 140°F (60°C) can cause a serious burn in five seconds or less. When the liquid is hotter, damage occurs faster, often resulting in burns severe enough to require specialized medical treatment, including potential surgery or skin grafting. Acute symptoms include blistering, significant pain, and inflammation, which can temporarily impair taste sensation or lead to difficulty swallowing.
How Temperature Contributes to Disease Risk
Beyond the acute danger of a burn, habitually drinking very hot beverages is linked to chronic health risks, specifically a higher likelihood of developing cancer. The International Agency for Research on Cancer (IARC), the cancer-research arm of the World Health Organization (WHO), classified drinking very hot beverages as “probably carcinogenic to humans.” This classification applies to any drink consumed at 65°C (149°F) or above. The risk is specifically associated with Esophageal Squamous Cell Carcinoma (ESCC), a cancer of the esophagus.
The mechanism involves repeated thermal trauma to the esophageal lining. Consuming liquids above the 65°C threshold causes continuous injury and subsequent repair, leading to chronic inflammation and an increased rate of cell turnover. This repeated cycle of damage and regeneration is thought to increase the probability of cancerous changes developing within the tissue. Studies in populations that traditionally consume beverages like maté or tea at temperatures around 70°C, such as in parts of South America, Asia, and East Africa, have shown a corresponding increase in ESCC risk.
The level of risk appears to be dose-dependent, meaning the danger increases with both the beverage temperature and the volume consumed daily. Individuals who drink a higher number of very hot cups each day face a substantially elevated risk compared to those who drink at cooler temperatures. This evidence emphasizes that the thermal injury itself is the damaging factor, separate from any chemical component of the beverage.
What Is the Safest Drinking Temperature?
To mitigate both the acute scalding risk and the long-term disease risk, health organizations recommend avoiding any beverage consumed at or above 65°C (149°F). This threshold represents the temperature at which the risk of thermal injury begins to significantly increase. For most people, the optimal temperature range for both safety and satisfying consumption is considerably lower.
Research suggests the preferred drinking temperature for hot beverages is typically between 130°F and 140°F (54°C to 60°C). One analysis pinpointed an optimal drinking temperature for coffee at approximately 57.8°C (136°F), balancing consumer preference with burn hazard reduction. A practical strategy for achieving this safe temperature is to allow a freshly brewed drink to cool for several minutes before taking the first sip.
A wait of three to five minutes after a beverage is poured is often enough to bring the temperature down below the 65°C danger zone. Adding a splash of cold milk or cool water can also immediately reduce the liquid’s temperature. Before swallowing, briefly testing the temperature with a small, careful sip can prevent accidental scalding and ensure the beverage is safe to enjoy.