It is only for the “seriously ill.”
In the General Instruction for the Rites of Anointing and Viaticum, the translator provides a footnote:
The word periculose has been carefully studied and rendered as “seriously,” rather than as “gravely,” “dangerously,” or “perilously.” Such a rendering will serve to avoid restrictions upon the celebration of the sacrament. On the one hand, the sacrament may and should be given to anyone whose health is seriously impaired; on the other hand, it may not be given indiscriminately or to any person whose health is not seriously impaired.
The words “it may not be given indiscriminately” are important. A priest must exercise prudent judgment when administering this Sacrament–that necessarily excludes anointing anyone who simply comes forward in line.
The actual text of the General Instruction says this in #8:
A prudent or reasonably sure judgment, without scruple, is sufficient for deciding on the seriousness of an illness; if necessary a doctor may be consulted.
Again, anointing anyone who comes forward in line does not meet the Church’s standard of a “prudent or reasonably sure judgment.”
Asking if anyone else needs to be anointed is certainly a good thing, but this also has to be accompanied by that “reasonably sure judgment” that each person is indeed a candidate for the Sacrament.