What is the ruling on placing an incense burner in front of worshippers in the mosque?

There is no harm in placing an incense burner or electric heaters in front of the worshiper. This does not fall under what some jurists have deemed disliked, namely facing fire, because they justified that by saying it is an imitation of the Magians in their worship of fires, and the Magians do not worship fire in this manner.