> Uncomfortable heat has nothing to do with temperature and everything to do with air humidity

That is not correct. Heat, wind and humidity all contribute.

In a dry air with no wind, your body creates a "hot and humid" bubble around it if you are not moving. A fan helps.

Humid but neither cold nor hot air may not feel great, but not that bad.

Hot and humid air with no wind, now that's bad.

Edit: I know because I added shades and fans.

27 centigrade with 80% humidity is a lot more uncomfortable for the human body than 33 degrees with 40% humidity. Likewise if the temperature is low, it's worse with high humidity and vice versa. The worst heat is the humid heat, and shade and fans cannot do much about it.