My son was wondering why a 104°F (40°C) hot tub feels so much hotter than a 104° day. I explained the difference between conduction and convection but we started wondering how hot the air would have to be to heat your body by convection at the same rate the water does by conduction.
I know that water conducts heat roughly 24X faster than air so the obvious but I assume completely incorrect answer is to multiply the difference in temperatures between human skin (~ 90°F/32°C) and the water by 24, but I’m not sure what the correct means of calculating it would be.
I’m aware an exact answer isn’t possible due to differences in air temperature/humidity, the fact that heating would slow down as your body heated up, etc, but am hoping there is some rough accepted guidance for estimating something like this.
Bonus points if it applies to sous vide vs. oven cooking, just because I’m curious about that too. :-)