This question studdenly appeared in my mind, A hypothetical liquid that is completely incapable of transferring (consequentially holding too, right?) Any heat in any way, how would it feel to touch it? We feel cold when heat gets out of our body and hot when it gets in right? Would it just feel perfectly neutral?
The feeling of hot or cold is actually just the feeling of heat energy entering/leaving your skin.
The basics: if something is cold, energy is moving from your hand into the cold thing. If something is hot, energy is moving into your hand from the hot thing.
If it cannot transfer energy at all, then it doesn’t feel hot or cold. Like when you take a shower at the perfect temperature where the water temp matches your skin exactly, and it doesn’t feel like anything. Or a very warm pool.
Your hand would overheat a little bit eventually because your body creates internal energy through being alive, which it radiates away through your skin to the surrounding air to maintain equilibrium. If your hand lost that ability, it would get a bit warmer internally. But your blood would maintain approximate temperature equilibrium, so it wouldn’t be too bad.
If you were in a pool of the stuff, you’d eventually cook yourself.
Source: got a physics degree a bunch of years ago and kinda remember some things. But I’m not 100% confident of any of this
What you’re describing is a perfect thermal insulator.
What does it feel like when you’re wrapped in blankets? You feel warm, despite the blankets generating no heat of their own. They do this by insulating you from the outside temperature.
It would feel like being wrapped in a warm blanket, and if you were fully submerged, you’d end up overheating as we’re constantly generating heat that we need to get rid of.
Like putting it in liquid that is at exactly your body temperature.
Answered in other comments, just to not spam my answer.
Okay, this is my undocumented, your average Joe type of guess, but here goes: as there is no heat exchange with its environment, I assume your hand would burn from its own heat.
If it was just your hand, your circulation would keep moving that excess heat out and into the rest of you, which would radiate most of it out like normal.
It’s a different story if you’re submerged far enough that there is not enough of you still exposed to discharge that heat.
