# What do metrologists mean by the “feels like” temperature and how is is different than the actual temperature?

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What do metrologists mean by the “feels like” temperature and how is is different than the actual temperature?

In: Physics

Air humidity and wind, to name a few examples, affect vastly on how the temperature feels like. F.ex. if it’s -10 celsius with wind, it might feel colder than -25 celsius without wind.

This is an oversimplification, but is true.

E: Grammar

Let say it’s 25°C in a room. Now turn on a fan. The temperature is same but it feels like colder when the fan in turned on.

To look at it a different way:

Actual temperature is how fast the air molecules are vibrating.

Feels Like temperature is how much the surface temperature of your skin drops when you step out into that air.

There are two things that can make one temperature feel hotter or colder; humidity and wind. High humidity causes cold to feel colder and hot to feel hotter. When it’s hot and humid, sweat can’t evaporate effectively because the air is saturated with water vapor, so it feels hotter. When it’s cold and humid, the water vapor in the air is more efficient at transferring heat out of your body than low humidity air, hence you feel colder.

Wind can make cold worse and hot better. When it’s cold out, wind pushes air across your body and through some clothes, making your cold. When it’s hot out, wind makes it feel cooler and it improves evaporation of sweat.

The actual temperature is, well, the actual temperature of the air, as measured by a thermometer.

We generate heat and dissipate it into the air around us. If it’s windy, we lose that heat energy more quickly; if it’s humid, we lose it more slowly. The temperature it “feels like” is the temperature that would make us lose that heat energy at the same rate assuming there was no wind and it was a standard humidity. So if it’s 20 and really windy, you lose energy as fast as you would if it was 10 and not windy.