Tactile maps in the sun

It looks like a lot of these are cast in metal for durability. I wonder how often does this go into consideration for placement in shade from the amount of heat they can build up? I like the comment on this photo, “In the direct sunlight, it was very hot to the touch.” In contrast, please don’t lick one of these in the Winter.

Is there any type of specialized paint that can help reduce heat transfer for those who use these? I suppose paint would be another source of wear and maintenance.