I am wondering if anyone has ever used a shemagh in high elevations during summer to protect their face from the intense sun. Mostly I am thinking about snow glare from extend walks across snowfields.
Would it get too/hot stuffy? Would I be better off just covering the bottom of my face with a regular bandanna? Either way they both seem like very multi use items.

A bandanna works. The only trick is the fastening method. I generally use a large safety pin.

The issue is that you can get a terrible sunburn if you have to cross a high altitude snowfield on a sunny day. It is extra bad because the radiation is coming up from the ground direction, not straight down from the sky. So, you tend to get a sunburn on the underside of your chin, the roof of your mouth, and the underside of your nose. Any sort of cloth is useful in blocking that.

I've also used a white silk balaclava, although it is not as multipurpose as the bandanna. Just suppose the wind whips that off your head. Now what are you going to use?

--B.G.--

Silk bandana is my go to multi use item. You can get them in a 42"x42" that would be large enough to use as a shemagh, but not near as heavy as a traditional cotton one. I've hardly ever needed to rig it shemagh stile, but I do stick it under my hat to shade the back of my neck quite often.

Also use as a pot holder, towel, prefilter, etc.

A bandanna is the cheap/easy route. No free lunch on making things stuffy-- you will be covering your face. A shemagh is usually made of loosely woven cotton, so it will breathe well and it will cover your whole head and face.

I like a Buff. It serves as scarf, face mask, full head cover with a ball cap.

Any thoughts on the sun blocking properties of a black mosquito head net?

I also like my buff, and was just using it as a balaclava last week on a 100-mile trip to keep the sun off my neck and face. Very light, kept me warm at night, and can be worn in a myriad of ways depending on what you need it to do (sun protection, stop sweat from dripping down your face, etc.).

Interestingly, some people I passed thought I was Muslim because I was using it to shield my whole face from the sun.