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Why we feel colder?

  1. Dec 12, 2006 #1
    We at normal body temperture and normal room temperture touch a block of ice and we feel it is cold. Not just our hands but our whole body as well.

    Why? Is it because we are use to transferring a certain amount of heat to the surrounding and if we touch a block of ice, we transfer much more heat than usual and so our body temperture decrease hence we feel colder. Does a decrease in temperture directly cause the feeling of 'coldness'? Is this the best explanation for novices?
     
    Last edited: Dec 12, 2006
  2. jcsd
  3. Dec 12, 2006 #2

    Danger

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    Partially. The main reason that it affects your whole body (in my opinion), is because of the amount of blood flow through the hands and its proximity to the surface. The blood itself is chilled by the contact, and then circulates that lower temperature throughout the body.
    I have found that when I'm really cold (and being an Albertan, I know cold), my best remedy is to run a sink full of water as hot as I can stand it and immerse my hands and wrists in it. I can feel the heat flowing down my back within a couple of seconds.
     
  4. Dec 12, 2006 #3
    So it's like the body is transferring energy to the ice and most that energy comes from the blood and other cells. These cells decrease in temperture and you feel cold. Does a decrease in temperture directly cause the feeling of 'coldness'?
     
  5. Dec 12, 2006 #4

    Danger

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    Pretty much. There is no such thing as 'cold', just as there is no such thing as 'dark'. There is only the absence of heat or light. The outflow of heat from the body to another place is perceived as 'cold'. The thermal conductivity of the material makes a huge difference. If you touch a piece of wood that's at 30 degrees C., it will feel reasonably warm (for non-metric types, body temperature is 37 degrees). If you touch a piece of steel that's at 30 degrees, it will feel quite cold. That's because it draws the heat away from your body far more effectively than the wood does. That's one of the main reasons that I gave up being a locksmith; working at -40C with Vise-Grips, when you can't wear gloves, is incompatible with arthritis.
     
    Last edited: Dec 12, 2006
  6. Dec 13, 2006 #5

    chroot

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    Blood flow is actually the dominant way for heat to be transferred from one part of the body to another. Keep in mind that even though water is a fairly poor conductor of heat, but has a very high heat capacity. Pushing water around is an excellent way to move heat.

    - Warren
     
  7. Dec 13, 2006 #6

    Danger

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    Of course, in my case that's Keith's Anti-freeze. :biggrin:
     
  8. Dec 13, 2006 #7
    Most of you surely already knows this:
    You know how can penguins preserve their heat even if they have wide flat feet? It's not because of fat or low-conductive tissues.

    It's because of an ingenuous mechanism (now copied from engineers!) of counter-flow heat exchange. Blood going down towards the feet exchanges heat with the blood moving up, so, when the blood arrives to the feet, it has the ground low-temperature, and so it cannot exchange heat with it!
     
  9. Dec 13, 2006 #8

    Danger

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    Yeah... right... :rolleyes:
    I've sure never heard of that. Neat bit of info.
     
  10. Dec 13, 2006 #9
    Is there a thing as heat? Would you say the underlying reason for feeling cold is a drop in temperture in the body. The reason for this drop is heat outflow. So heat is a theoretical entity (even more so than temperture because it can't be directly measured by a device?) to account for differences in tempertures in bodies.
     
    Last edited: Dec 13, 2006
  11. Dec 13, 2006 #10
    It also has alot to do with the way nerve endings communicate to the brain. Its like when you get into a really hot bath -- you actually itch because your brain is trying to process what is wrong but can't quite make it out. In a sense, touching a block of ice making you cold is your body saying -- something ain't quite right here, so stop doing that!!!!
     
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