I was thinking about how horrible cold hands (or other body parts) can feel when they are touching you. Even if someone gets out of bed for a few minutes and comes back in and touches you, they feel strikingly cold.
I understand that substances like metal and porcelain feel much colder to the touch than wood or plastic because metal and porcelain are more efficient conductors of heat, and thus can draw more heat away from the skin. How does the thermal conductivity of skin/flesh compare to that of other materials like steel?
I assume that even when someone has hands that feel cold, the hands are still well above freezing point, but how cold do hands and feet typically get? And is it purely physiological, or is there a psychological component as well, like a revulsion towards cold flesh?
Flesh must have a thermal conductivity not to far from about 0.6 W/mK, which is the conductivity of water. Steel is about 50. To give you a sense of the metals, Bismuth is 8, Stainless steel is 15, Aluminum is 150 and Silver is 400. So flesh isn’t that close, though you could say Bismuth is closer to flesh than to Silver, even in a geometric sense.
Hands and feet are never going to be cooler than their environment, except if the environment is an oven - and even then only temporarily. If the hands and feet are alive they must be exporting some heat and so must be somewhat warmer.
If they are not alive, they should come to match the environment. This suggests a real good excuse to have a psychological effect. You’re supposed to get the creeps when you think you’re holding a corpse
Flesh must have a thermal conductivity not too far from about 0.6 W/mK, which is the conductivity of water. Steel is about 50. To give you a sense of the metals, Bismuth is 8, Stainless steel is 15, Aluminum is 150 and Silver is 400. So flesh isn’t that close, though you could say Bismuth is closer to flesh than to Silver, even in a geometric sense.
Hands and feet are never going to be cooler than their environment, except if the environment is an oven - and even then only temporarily. If the hands and feet are alive they must be exporting some heat and so must be somewhat warmer.
If they are not alive, they should come to match the environment. This suggests a real good excuse to have a psychological effect. You’re supposed to get the creeps when you think you’re holding a corpse.