A large observational Chinese study published in the Annals of Internal Medicine in 2018 linked drinking hot tea to esophageal cancer. But the study found this increased cancer risk only in men who regularly drank “burning hot” tea and also drank at least one alcoholic beverage a day or smoked cigarettes (both risk factors for esophageal cancer). The risk was not seen in women, and not in men who drank tea that wasn’t burning hot or who didn’t also drink alcohol or smoke. Even among those men, the increase in absolute risk appeared to be tiny.
It’s true that the International Agency for Research on Cancer has judged long-term consumption of very hot beverages (over 150F) to be “probably carcinogenic,” based largely on studies in South America linking yerba mate, which is traditionally drunk very hot, to esophageal cancer.
It’s theorized that the very hot temperature damages cells in ways that can promote tumors. But most people don’t drink scalding hot beverages. The temperature of hot beverages drops quickly, depending on the delay before consumption, amount of liquid, thermal properties of the cup, and room temperature-plus the amount of milk, sugar, and whatever else you may add. Most people prefer temperatures of about 140F or less, according to some studies, and they usually wait until their beverages cool down somewhat before drinking.