If you live in an older home, you may still have radiators as part of your heating system. These units usually have lots of tightly compacted coils that are installed up against a wall. These coils collect of dust and dirt, so it is a good practice to dust those coils once in a while to keep them clean.
Use a dusting wire brush with a long pole to insert into and between the different baffles of the radiators. This helps get inside those hard to reach spots to dust the unit and every capture lint or other debris that may have gotten stuck inside the unit.
Here is a quick video from unlocked mind media.