[mixedmath]

I think this is easier to see if we consider a milliter of water and stick with celsius.

1ml of water weights 1 gram, and raising this ml of water one degree celsius is 1 (little c) calorie.

Drinking 1 ml of ice water (at about 0 degrees celsius) and raising it to body temperature (at about 37 degrees celsius) thus takes about 37 (little c) calories.

Thus drinking a liter of ice cold water would consume about 37 (big C) Calories.

[leereeves]

And a pound of fat contains 3500 Calories (kcal), so drinking about 100L of ice water would consume one pound of fat.

One could drink 15L per day (about one liter per hour and 5x the recommended minimum intake) and burn about one pound of fat per week.

[brador]

Or just sit in an ice bath. Also, I wonder if the reverse is true: if you drink a warm drink does that cause calories that would have been burned heating you to not be burned?