Temperature is related to the average kinetic energy of jostling molecules. It is measured using a thermometer in degrees Celsius, Fahrenheit, or Kelvin. Thermal energy refers to the total energy of all the jostling molecules in the coffee. Your friends' smaller cups of coffee will have less thermal energy than the larger pot of coffee because these smaller cups contain a fewer number of moving molecules. How much heat is transferred from coffee to your mouth depends on difference in temperature between the coffee and your mouth. Your coffee will seem hotter if your mouth is colder from drinking ice water.