When will your drink be the right temperature?
The rate at which a hot object cools is proportional to the temperature difference between the object and its surroundings: T(t) = T_room + (T_initial - T_room) × e^(-kt). The cooling constant k depends on the container material, surface area, and whether there's a lid. A typical ceramic mug of tea (100°C) reaches drinkable temperature (60°C) in about 4-6 minutes in a 22°C room. An insulated travel mug takes 15-20 minutes. Blowing on hot liquid works by accelerating evaporative cooling — evaporation removes 2,260 joules per gram of water, making it the most effective cooling mechanism. Adding cold milk drops the temperature by about 5°C per tablespoon. The "ideal" drinking temperature for coffee and tea is 57-65°C; above 65°C risks burns to the mouth and esophagus.