system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If 1 calorie is the amount of energy required to heat up 1ml of water 1 degree, why cant I drink 1 liter of 0c water and burn off 36,000 calories when my body warms it back to 36c?

Sorry for the very long title!

I've read over and over that 1 calorie is the required amount of energy to heat 1 gram/ml of water 1 degree. So surely our body must burn off calories, just by heating chilled water... except it doesn't. Why?
gpt
You're confusing small-c calories with big-C Calories, also called kilocalories.

A calorie will indeed warm 1 cc of water by 1 degree Celsius. A Calorie will warm 1 *liter* of water by 1 degree Celsius. So your plan would work, but you need 1000 liters of ice water, not one.