Remember, the human body cools itself through evaporation.
Sweat produced by the body needs to evaporate to "cool" the body.
Not to go too in depth on Relative Humidity, wet bulb and dew point, but the more moisture in the air (relative humidity) the harder it is for the sweat to evaporate.
Example. Indoors you're t-stat could read 74, but you seem to be hot. In another house, your t-stat could read 74, but you seem a lot cooler. The difference? One house the RH (relative humidity) could be 60% (high) and the other house it may only be 45%. The lower the humidity, the easier it is for the body to cool itself.
Heck, in one house you could feel "cooler" at 78F than in another house at 73F depending on the humidity.
One reason why fans help cool the body. The air flowing over the body helps the sweat evaporate itself.
May be science 101 for some, but it took me a long time to figure out why I didn't need A/C in the car up north (which I didn't have), but you darn well better have a/c in your car in the south. Up north, I could drive 60mph and roll the windows down on a hot day and get cooled off. Down south? No way. The difference? Higher humidity "down south". Same airflow going over the body (with car windows rolled down) however, with more moisture in the air (down south) it didn't help my body to "breath", so I stayed hot.
After only my first two two weeks in N.C, I broke down and bought a new car with A/C because I sweat like a pig naturally. And I always thought cars with A/C were for wussies.
For the record, this was taken in the shade a little while ago. The price you have to pay for little snow

(temperature is "T1").
