So, after it didn't happen though my 2 years in Namibia, I've finally done it. I've become one of those people. I now carry an umbrella everywhere.
At first I was against such people, thinking that they were too conscious of their complexion. Then I walked around with an umbrella one day and the decrease in the heat I felt was immediate. It's a portable shade. Though walking with one does require a bit of practice. Knowing which way to tilt it to get the full benefit of it's shade, how high to raise it when on a busy street so that others can pass by or so you don't hit displays, getting used to the gusts of wind and how to keep your umbrella in control, switching hands so that one hand doesn't get too tired all of this takes some practice.
I of course find additional benefit from my umbrella.
1-I can use it to shade/hide my face when I'm feeling too stared at. You should see how far down guys have stooped to try and see under my umbrella
2-I specifically use it to block the view of people who are already staring too hard.
3-It enforces my personal space so that men find it harder to "brush by" me.
4-And even when they try to the metal ends and getting hit by my umbrella (because I will hit them with my umbrella if they are crowding me on my little patch of the sidewalk, as I did to two guys this morning) makes me feel a bit more vindicated.
Of course it has come in handy on those few occasions I've been caught in the rain too.