Why do certain metals feel colder to the touch compared to other materials, even when they are at the same temperature?
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Your body senses temperature as how quickly heat is leaving your body. Very slow heat transfer means “The air / this thing is almost as hot as I am!” Very fast heat transfer means “The air / this thing is much colder than I am!”
Metal and water are much, much better at accepting heat than wood or cloth are. Thus, even at the same temperature, they “feel” colder, because they are still sucking heat out faster.
(Conversely, this is also why, *above* body temperature, hot metal and hot water are more painful or burn you faster than hot wood or hot cloth do! They give up their heat to you faster as well.)
Metal is really good at absorbing and distributing heat. this is called thermal conductivity. The metals with the highest thermal conductivity are copper and aluminum and the lowest is bronze and steel.
because room temperature is lower than body temperature, this means whatever you touch at room temperature will conduct heat away from you, metal of course being a good conductor of heat will conduct heat away faster, making it seem colder initially until it reaches thermal equilibrium
It makes sense if you really think about why our skin can sense temperature in the first place. In nature, you never need to know the actual temperature of something. All you functionally need to know is “how long can I touch this thing before I get burnt/frozen”. It’s like triage in a way. A hot thing that conducts heat really quickly will burn you really quickly, regardless of it’s actual temperature, so that’s what your body needs to know.
You also don’t have a “wetness” sensor. It’s the same reason you can grab a piece of clothing and it’s hard to tell if it’s wet or cold. A cold cloth and a wet cloth will both pull heat away from your skin faster than a warm dry cloth because water is a pretty good conductor. You will use other queues like weight and texture to try to make it out, but sometimes it’s difficult.
Most of the counterintuitive things about how temperature “feels” comes down to two facts.
The first fact is that heat energy flows from hotter things to colder things, that is to say, from a higher temperature to alower temperature. And a key detail of this fact is that some materials are more conductive, so heat flows *faster.*
The second fact, and this is the counterintuitive one, is that nether a thermometer or your body can actually sense the temperature of the outside. They can only sense the temperature of themselves.
Your body has nerve sensors for heat and cold, but these cannot tell how hot something is outside the body. They can only tell how hot or cold your fingertip is when you touch something. Did your finger go below expected temperature or did it go above it?
But unlike a thermometer, your body can’t actually let itself reach the temperature of what it’s touching. Pick up an ice cube and your fingertips might drop a few degrees. Your body is immediately working to warm your fingers back up, because blood from the rest of your body is coming in at body temperature. Your body isn’t telling you what the temperature of the ice cube is, it’s actually telling you “we’re losing heat from our fingertips.”
So when you touch something, it’s not so much a measure of what the temperature of the object is, but rather how much heat is entering or exiting your body. And you can see why this is so – if your body wanted until the fingers were frozen to say “yeah that’s actually pretty cold” or waited until they cooked to say “oh that’s hot” it would be a pretty useless alarm. Something feels hot when it’s transferring a lot of heat into you. Something feels cold when it’s transferring a lot of cold away.
How the rate of heat transfer is proportional to the difference in temperature. If something is 10 degrees colder than your skin, it will transfer heat away at twice the rate of something 5 degrees colder than your skin. But something which is 5 degrees colder and twice as conductive as something 10 degrees colder will transfer at the same rate, and thus feel the same.
Metal feels colder than other materials when it’s cooler than your body, because heat leaves your body faster.
But metal also feels *hotter* than other materials when its warmer than your body, because heat *enters* your body faster.
Metal at exactly your skin temperature doesn’t feel like anything, but this is a rare situation.
The human body feels whether or not heat is entering or leaving its tissues. All materials have something called a “specific heat” which is the amount of heat that must be added to a given amount of the material in order to raise its temperature by some amount. Metals have very low specific heats, meaning that they suck up heat rapidly. Metals feel colder at the same temperature because they are very thermally conductive, and sap the heat from your tissues more quickly than other materials. This is why they feel ‘colder’ at a given temperature than most other things.
Metals are good conductors of heat.
When you touch room temperature metal, heat energy is carried away from your skin much more quickly than it is when it touches room temperature plastic or glass.
This makes metal feel colder.
Because your body temperature is higher than room temperature. And if you’re wondering why the air doesn’t feel as cold as the metal, it’s because metal does a much better job at transferring heat than air.
Lots of other people here have explained the reason. But I thought I would post a short (3 minute) video that could be helpful if the text answers aren’t clear enough.
When we feel “cold”, what we’re actually perceiving is “getting colder” rather than “being cold”. Same thing with warmth.
The best example I can think of to illustrate this is if you run freezing cold hands under room temperature water, it’ll feel hot, not because the water is hot, but because your hands will be rapidly warming up.
Metal loves to share heat, it’s an inherent property to a lot of metals that it really wants to be the same temperature of the things around it (this is referred to as having high thermal conductivity). So when you touch it, it’s at room temperature and your body is at, well, body temperature (which will be warmer), so you heat it up slightly, but that means it’s sapping heat from you
You feel this cooling down effect which is perceived as feeling cold
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