On those hot summer days it can be really hard to keep your face cool while on the go. You can buy portable hand fans, but carrying it around is a real hassle. What can I do to keep my face cool while on the go?
Keep a wet towel around your neck. Wipe your face from time to time. (Nethack fans will do it with #wipe)
Evaporation of water on your skin will cool your skin. Physical reason is latent heat.
Cooling base of neck has a medical reason (2009, Han et. al) resulting in cooler body. Blood vessels near skin transport a lot of blood towards the head and can be cooled by the wet towel. This helps to regulate whole body temperature.
You can make a mobile face cooling hat with a portable fan (I'd suggest something like this), some ducktape, and a hat (I'd suggest a hardhat). Just tape the fan to the hat in such a way that it's touching facing your face and BAM! Mobile face cooler.
An idea similar to Wipqozn's (But real and looks decent)
$9.99 on Amazon There is assorted colors available.