Is it hot or cold?

Have you ever wondered what means that something is cold or hot? Why those windy days seem to be colder than others?
Well, everything is based on understanding what the temperature is and why it is that something seems hotter or colder.

The temperature is a way we have to measure the agitation of the particles that form a body. Now, when we say that something is cold … is its temperature low? And if we say that something is hotter to the touch … is its temperature high?
Not necessarily!
We must bear in mind that when we touch something we are not feeling the temperature of the object in our hand, what we feel is the temperature of our hand.

So … if we have two objects at the same temperature, can it seem that one is colder than the other?

Yes! Do the test with the things you have around you, at your table … they are probably at very similar temperatures (at room temperature).

Don’t you think that the wooden pencil is hotter than the metal pen? Does your notebook seem to be hotter than your metal keys?

This is because metal objects are better temperature conductors than paper or wood (which are insulators). That’s why when you touch them, they extract more quickly the heat from your hand, and that’s why they seem to be colder (because the heat of your hand is coming out faster).

So you can see that the temperature is not necessarily the same as the cold or hot that we notice something. Saying something is cold or hot also has to do with how the heat is transferred.

And little by little we get to answer the first question, why when it is a windy day we feel it like a colder day. Have you ever heard about thermal sensation, right?

Anyday, there is 5 ºC outside but when the air blows it seems that the temperature is lower. Among other things, it is because the air can be cold … but basically, it is because the air better removes the heat from your body. And since what you are feeling is our body’s temperature, the temperature seems lower. Does not it make sense? We produce heat, always, when we are standing or moving. This generated heat covers us and makes a protective layer. However, the wind speed causes that layer of protection to be transferred to the environment and we feel colder.
To finish, we ask you this question: You are on the street, the temperature is low … what’s better, to be still or to run? What do you think?

The answer, great as always, via One Minute Physics

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