Distinguished by her plain robe and the bronze serpent lemniscate pendant she wore on a leather thong around her neck, she was already surrounded by a small crowd of people seeking healing. They stood quietly, watching with a mixture of hope and awe as she examined an infant lying on her lap.
-Luck in the Shadows by Lynn Flewellin
Whenever PC clerics enter a village with no temple, they should be mobbed by people looking for healing (mostly from disease, which is too bad for the villagers, because you get Cure Light Wounds way before you get Cure Disease).
Before any other business in a small town, a cleric would probably have to do some doctoring – making Heal checks, at the very least. Sometimes this will lead to exposure to dangers like filth fever, or even the occasional demonic possession.
This doesn’t apply to all Leader-type classes. People don’t go to warlords so much because their healing is, as far as I can tell, entirely psychosomatic. No one takes their sick baby to the gym teacher to obtain his exhortation to “walk it off”.