Does hot air blowing across a surface have the opposite effect of wind chill ? Does it raise the temperature ?

Question

I was driving in Phoenix one pleasant 117 degree day, i was doing 75mph with my arm out the window. Was I cooking my arm ?

Answer 1

Neglecting evaporative cooling due to sweating which complicates the explanation, heat moves from higher temperature to lower temperature in the absence of work (such as an air conditioner).

If the outside temp is 117 and your body temp is 99, heat will flow into your body (the body compenstaes by sweating that cools the skin, but we are neglecting that for now).

In moving air (called convective heat transfer) the rate of heat transfer goes up many times because a boundary layer of stagnant air does not form (air is a pretty good insulator). So, if you are blowing 117 air past your body, in the absence of sweating, the rate of heat transfer into your body will be greater.

Why is a hair dryer blowing hot air? To more quickly raise the temp of water to evaporate it.

So, whether you were "cooking" or not is not an easy answer. Your body cools itself by evaporative cooling that will help offset the heating. Chances are in Phoenix, becasue the air os so dry, the evaporation is very rapid and cooling is adequate. This is one reason dehydration in hot climates is so dangerous is becasue your body doesn't have the excess water to provide sweating so the heating of the body gets worse.

Volcanoes????? Learn some science

Answer 2

No, there is not an opposite effect. Let's say that you had a pail of water at body temperature (98.6 degrees). Exposing it to fast moving hot air (117 degrees) will not increase the temperature of the water beyond 117 degrees.

Let me explain the concept of wind chill to you. Let's say that it is 35 degrees out with no wind. A pail of water exposed to this temperature would not freeze because the freezing point is 32 degrees. Now let's say that the temperature remains at 35 degrees but a strong wind blows across the pail of water. The water will cool off faster than it would in still air because the wind carries heat away from the water more quickly than still air. But even though the heat is carried away quicker, the temperature of the water would not drop below 35 degrees. When someone says it is 35 degrees out with a wind chill of 20 degrees, what that means is that heat is being taken away from an object as quickly as if the object were exposed to 20 degree UNMOVING air. However, the temperature of the object will only drop to 35 degrees, NOT 20 degrees.

Answer 3

No! Take a look at volcanic mountains. What do you see? Snow, because the hot air and lava coming out of the volcano cools the air and makes snow and ice in that area.

Answer 4

No cops around, huh?! the answer is no, the Wind Chill factor does not include the temperature of the current. the main criteria is velocity (V).

Answer 5

The question is the wind blowing the answer .

Answer 6

Your hand might have been hot because of the humidity or your body condition but not because of the wind.

Answer 7

Probably felt like it. Death Valley weather stations would know more about how to answer this.

Answer 8

Your hand was moving and not the air.

Answer 9

NO