If you have ever watched the famous Christmas movie A Christmas Story you are likely to remember the scene where the character Flick gets his tongue stuck to a metal pole. I remember when I was little that I did not believe that you could actually get your tongue stuck to a pole, but it turns out that if it is cold enough you actually can. If you idealize the system of your tongue and the metal pole to an isolated system you can simply use the equation Q=mcΔT. If the temperature of the water on your tongue reaches 32℉ then it will freeze and consequently freeze your tongue to the pole. If your body temperature is 98.6℉ and the outside temperature is 23℉ your tongue will end up freezing to the pole as demonstrated below.
Cwater = 1.0 kcal/kg℃ Ciron =0.108 kcal/kg℃ Lf = 79 kcal/kg
mpole = 70kg mwater = 0.018kg
(0.018kg)(79kcal/kg) + (0.018kg)(1.0kcal/kg℃)(37℃-0℃) = -(70kg)(0.108kcal/kg℃)(-5℃- Tf)
Tf = -0.44℃