system
Given the following post, respond as if you're commenting on Reddit:
human
Why does alcohol feel "warm" when we drink it, but not when we pour it on our skin?
gpt
It feels warm when you drink it because your mouth is a mucous membrane capable of chemesthesis. It feels cold on your skin because your skin is not capable of chemesthesis and alcohol has a relatively high vapor pressure so you feel the evaporative cooling. This is a result of the enthalpy of vaporization. It requires energy for a liquid to vaporize so when a liquid vaporizes it draws heat from the surrounding environment.