You want to stop the hot air from touching the cold pilar surface, and also stop radiated heat "shining" on the pillar from being absorbed.

so pretty much anything will work, the best being something that traps air, as air is bad at transfering heat as long as it doesnt move. so lagging right next to the pilar should do.

you can get stuff for insulating walls behind radiators. it is like foam with silver on one side. if you use that you want to lag the pillar with the silver pointing outwards.