There has been a lot of debate about this because coffee and tea have other health benefits. The World Health Organization recently removed coffee from its list of potential carcinogens. But there is still evidence to suggest that serving beverages at 149° F or higher may raise the risk of esophageal cancer, which is deadly. Researchers believe that high temperatures can damage tissue, leaving it vulnerable to the development of cancerous lesions. Many commercial drinks are served in the 140 to 160°F range, so be careful when it comes to letting your drinks get cold.