Our friend here has probably never had to squint into the setting sun in search of the PAPI whilst on final for RW28 at Broome.
What has this got to do with protection from the sun? The circumstances of this situation are highly specific - I concede a baseball cap or any headwear with a suitable peak could be useful in this (highly specific) situation.
When it comes to protection from the sun, bear in mind that when the sun is low (near the horizon) it has only a tiny fraction of the destructive power it has when higher up.