system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does water feel significantly colder than air?

I suppose this could work for hotter temperatures of water but I'm mainly focused on talking about room temperature air and water. Why is a 70° room much more comfortable than a 70° pool of water? I mean, that 70° pool literally feels like ice.
gpt
Water is much denser and has a much higher heat capacity than air.  That means that water can quickly absorb a lot of heat and air can't.

Your body tries to maintain a constant 98.6 degree internal temperature and 70 degree air removes heat (you generate heat) at a nearly perfect rate to stay there.

70 degree water removes too much heat and you feel cold.