Drinking very hot beverages raises the risk of esophageal cancer, and the evidence behind that claim is strong enough that the International Agency for Research on Cancer now classifies drinks above 65 °C (about 149 °F) as “probably carcinogenic to humans.” The risk comes from temperature itself, not from the type of drink. A systematic review of the available literature found that the amount of tea or coffee consumed mattered far less than how hot it was when it reached the throat.1PubMed Central. High-temperature beverages and Foods and Esophageal Cancer Risk — A Systematic Review Beyond cancer, scalding hot liquids pose burn risks, can leach chemicals from disposable cups, and may even dull your sense of taste over time.
Where the Danger Line Sits
The 65 °C threshold that the IARC flagged is not an arbitrary number, but it does come with some nuance. In a sensory study that asked people to drink progressively hotter coffee, participants on average reported the liquid as “too hot” at around 66 °C, though individual pain thresholds ranged widely from 58 °C to 71 °C.2PubMed Central. What Temperature of Coffee Exceeds the Pain Threshold? Pilot Study of a Sensory Analysis Method as Basis for Cancer Risk Assessment The preferred drinking temperature in that same study averaged 63 °C, which already bumps against the IARC cutoff. Separate research on oral contact with hot food found that temperatures around 46–48 °C felt “just comfortable” for sustained mouth contact.3Safety. Injury Threshold of Oral Contact with Hot Foods and Method for Its Sensory Evaluation
The gap between those numbers matters. Your mouth’s comfort ceiling is well below the temperature at which cancer risk begins to climb, which means the liquid racing past your tongue and down your esophagus can be hotter than what your mouth registers as tolerable, especially if you gulp rather than sip. Some people also habituate to heat, so a drink that would make a newcomer wince feels normal to someone who has been drinking it that way for years.
How Heat Damages the Esophagus
The esophagus is lined with a thin, delicate layer of cells that is not designed to withstand repeated scalding. Chronic exposure to very hot liquids injures this lining in two ways. First, repeated thermal irritation triggers ongoing inflammation, and that inflammation can spur the body to produce reactive nitrogen species and, eventually, cancer-promoting compounds called nitrosamines. Researchers have found a distinctive mutation pattern in the TP53 tumor-suppressor gene in esophageal tumor samples from populations known for drinking very hot beverages, a pattern consistent with this nitrogen-driven damage. Second, heat weakens the barrier function of the esophageal lining itself, making it easier for any other cancer-causing substances already present in the throat to penetrate into deeper tissue.4PubMed Central. High-temperature beverages and Foods and Esophageal Cancer Risk — A Systematic Review – Section: Discussion
That second pathway is especially relevant for people who smoke or drink alcohol. If your esophagus is already exposed to carcinogens from tobacco or ethanol, heat damage pries the door open wider. The two risks multiply rather than simply add up.
The Evidence from Tea, Coffee, and Yerba Maté
The most dramatic numbers come from studies of yerba maté, a caffeinated infusion popular in South America that is traditionally sipped through a metal straw from a shared gourd. That straw delivers the liquid almost directly to the back of the throat at close to its full temperature, bypassing much of the cooling that happens when you sip from a cup’s rim. A review of maté studies found that cancer risk climbed with both daily quantity and temperature, with the highest reported odds ratio reaching 34.6 for women drinking a liter or more daily at high temperatures.5PubMed. Cancer and yerba mate consumption: a review of possible associations A large pooled analysis of two case-control studies in South America confirmed that the risk of esophageal squamous cell carcinoma rose steadily with increasing maté temperature, and the association was statistically stronger at “very hot” than at “warm” drinking temperatures.6Cancer Epidemiology, Biomarkers & Prevention. Maté Drinking and Esophageal Squamous Cell Carcinoma in South America: Pooled Results from Two Large Multicenter Case–Control Studies
Tea drinkers in other parts of the world show the same pattern. A prospective study in Golestan Province, Iran, where black tea is consumed throughout the day at high temperatures, found that people who drank tea at or above 60 °C had roughly 40% higher risk of esophageal squamous cell carcinoma compared to those who drank it cooler. Those who described their preference as “very hot” had about two and a half times the risk. And the combination of high temperature and high volume, 700 mL or more daily at 60 °C or above, was linked to roughly a 90% increase in risk.7PubMed Central. A prospective study of tea drinking temperature and risk of esophageal squamous cell carcinoma
Data from the UK Biobank, which tracks hundreds of thousands of participants, reinforced the pattern in a Western population. Compared to people who drank fewer than four cups a day at warm or lower temperatures, those who preferred their tea or coffee “hot” and drank more than eight cups daily had roughly triple the risk of esophageal squamous cell carcinoma. For people who preferred “very hot” drinks at the same volume, the risk was about five to six times higher.8British Journal of Cancer. Hot beverage intake and oesophageal cancer in the UK Biobank: prospective cohort study
Temperature and Quantity Are Independent Risk Factors
One of the more practically useful findings in this research is that temperature and volume each raise risk on their own. In other words, drinking a small amount of scalding tea is worse than drinking the same amount lukewarm, and drinking large quantities of mildly hot tea is worse than drinking a small cup at the same temperature. A systematic review that looked at mutual adjustment for these two variables confirmed that both were independent risk factors for esophageal cancer.1PubMed Central. High-temperature beverages and Foods and Esophageal Cancer Risk — A Systematic Review That means you can reduce your risk meaningfully by addressing either one. You do not have to give up your six cups of tea a day if you let each one cool for a few minutes before drinking.
The Gap Between Serving and Drinking Temperature
Coffee industry standards recommend holding brewed coffee at 80–85 °C (roughly 175–185 °F), and research on serving practices has found that spills at those temperatures can cause serious burns.9International Journal of Medical Science and Clinical Research Studies. How to Safely Drink Your Coffee: An Observational Study of Coffee Serving Temperatures and Scald Risk Considerations That serving temperature is well above the 65 °C risk line, and well above the roughly 46–48 °C range where mouth tissue starts to feel uncomfortable on sustained contact. In practice, most people do not drink their coffee the moment it is served. The liquid cools in the cup, you blow on it, you take cautious first sips. By the time you are drinking steadily, the temperature has usually dropped below the danger zone.
The trouble arises when you habitually skip that cooling phase. If you pour your coffee and start drinking within a minute or two, or if you refill from a carafe that keeps the liquid at serving temperature, you may be regularly exposing your esophagus to liquid above 65 °C. The Iranian tea study found that shorter time between pouring and drinking was itself a risk factor for esophageal cancer.7PubMed Central. A prospective study of tea drinking temperature and risk of esophageal squamous cell carcinoma A practical rule of thumb: if you cannot hold a comfortable sip in your mouth for several seconds without wincing, it is still too hot for your esophagus.
Microplastics and Chemical Leaching from Disposable Cups
Temperature creates a separate problem when hot drinks meet disposable paper cups. Most paper cups are lined with a thin plastic film to prevent leaking, and when hot liquid sits against that lining, compounds can migrate into the drink. Research using gas chromatography found that hot water in disposable cups leached several chemicals including phthalates, styrene, and vinyl chloride, all of which have raised health concerns at higher exposures.10LabMed Discovery. Microplastics associated contaminants from disposable paper cups and their consequence on human health The leaching happens within minutes of contact.11PubMed. Drinking hot beverages from paper cups: Lifetime intake of microplastics
The concentrations involved are small in any single cup, but for someone buying a takeaway coffee every morning for decades, the cumulative exposure adds up. Using a ceramic mug or a glass travel cup eliminates this issue entirely, which is worth considering if you are already thinking about how to make your hot-drink habit safer.
Hot Drinks and Taste Sensitivity
An underappreciated consequence of habitual very hot drink consumption is what it does to your palate. A study comparing people who regularly drank very hot beverages with those who preferred moderate temperatures found that the very-hot group was less sensitive to sweet and salty tastes. Higher frequency of very hot drink consumption made the dulling of sweet taste even more pronounced.12PubMed Central. Impact of Very Hot Drink Consumption Habits, Age, and Sex, on Taste Sensitivity This creates a feedback loop: as your taste buds become less sensitive, you may add more sugar or salt to compensate, and you may also tolerate even hotter temperatures because the thermal discomfort is part of what your mouth has learned to ignore.
Scald Burns and Children
For young children, the risk from hot drinks is not cancer but acute burns. Scalds from hot liquids are one of the most common burn injuries in children under two, and a substantial share of those scalds involve an adult’s hot drink. A study of pediatric burns in Lithuania found that scalding was the leading cause of burns in children under two, with a major portion caused by parents’ hot drinks being pulled off tables or spilled during handling.13PubMed. Epidemiology of paediatric burns in Lithuania: focus on a vulnerable population exposed to the risk of scalds at home without hot tap water supply In a U.S. study of non-tap-water scalds in children, roughly 90% involved hot cooking or drinking liquids.14PubMed. Preventing unintentional scald burns: moving beyond tap water
Children’s skin is thinner than adults’, so a temperature that causes a mild sting for you can produce a deep burn on a toddler. Keeping hot drinks away from table edges and out of reach is straightforward advice, but it bears repeating because the injury pattern is remarkably consistent across countries and decades of burn-unit data.
What About Reflux and Barrett’s Esophagus?
People with gastroesophageal reflux sometimes worry that hot drinks worsen their condition or contribute to Barrett’s esophagus, a precancerous change in the esophageal lining driven by chronic acid exposure. A large case-control study initially found that hot or extremely hot coffee was associated with Barrett’s esophagus in unadjusted analysis, but once the researchers accounted for other risk factors, the association disappeared. Neither coffee nor tea, at any temperature, showed a significant link to Barrett’s esophagus after adjustment.15Clinical Gastroenterology and Hepatology. Coffee or Tea, Hot or Cold, Are Not Associated With Risk of Barrett’s Esophagus The cancer risk from hot drinks appears to be specific to squamous cell carcinoma of the esophagus, not to the adenocarcinoma that Barrett’s esophagus can lead to. These are biologically different cancers arising in different cell types, and the thermal-injury mechanism does not seem to drive the reflux-related pathway.
Hot Drinks and Digestion
Not all effects of hot drinks are negative. A small trial in older adults found that a warm (60 °C) protein-containing drink emptied from the stomach faster in the first five to ten minutes after ingestion compared to the same drink served cold (4 °C). The warm drink was also associated with slightly higher hunger levels afterward.16PubMed Central. Consumption of hot protein-containing drink accelerates gastric emptying rate and is associated with higher hunger levels in older adults For older adults struggling with poor appetite or slow gastric emptying, a warm drink before or with a meal could be mildly beneficial. At 60 °C, that drink sits just below the 65 °C risk threshold, which suggests that drinking at warm-but-not-scalding temperatures may give you the digestive nudge without the tissue damage.
Getting the Most from Tea Without Overheating
Temperature also affects what ends up in your cup nutritionally. A study on Turkish green tea found that brewing at 85 °C for about three minutes produced the highest levels of EGCG, one of the catechins associated with green tea’s antioxidant properties, along with the best sensory scores for taste and aroma. Longer brewing at that temperature actually reduced the yield of some beneficial catechin forms.17PubMed Central. Effects of different brewing conditions on catechin content and sensory acceptance in Turkish green tea infusions The practical takeaway is that boiling water is not necessarily better for extraction, and you do not sacrifice flavor or health compounds by brewing at a slightly lower temperature. By the time a cup brewed at 85 °C has steeped for three minutes and sat for another minute or two, it has likely cooled into the low 60s or high 50s, right around where the evidence suggests you can drink comfortably and safely.
For black tea and coffee, which are typically brewed with hotter water, the cooling window just needs to be a bit longer. Setting a timer for four or five minutes after pouring is a low-effort habit that brings most drinks below the risk threshold. If you are someone who has always bolted your first sip the moment the kettle clicks off, adding a short wait is probably the single most impactful change you can make to reduce your risk from hot beverages.