I have been wondering about this particular issue for quite some time now. It feels like I should know this as a master's student in physics. The questions are, essentially, the following:
- What is the physical quantity that is measured by the human skin, i.e., what is causing the sensation of hot and cold that we are feeling?
Obviously, this quantity cannot be temperature - when entering a cold bathroom in the morning, you will definitely feel a significant difference between the floor tiling and the bathroom rug, even though both should be at the same temperature. Which leads to the second question:
- Which material parameter determines whether two media that have the same temperature feel hotter / colder compared to each other?
My best shot for question 1 would be some sort of energy flux $J$, which would depend on temperature difference $\Delta T$ between skin and object and a heat capacity $c$ like
$$J \propto \Delta T\cdot c $$
so the bathroom tiling feels more extreme than the rug just because its heat capacity is higher (i.e., it loses more energy if the temperature drops). This would also explain why a regular beam of water from the sink can feel hot after a snowball fight (the dependence on $\Delta T$). Is this reasoning correct?
What is bugging me about this is that this heat sensation would not depend on the heat conductivity of either material at all. It feels though like this should play a role, but I cannot wrap my head around a way to include it.
Happy for any answer that may help.