When you return to the campgrounds in the afternoon and notice that you have blisters or other foot problems, you must sign up immediately on the list at the FCC. The list is posted near the entrance of the FCC in the hallway.
After signing up, go take a shower (first aid workers don't like to treat dirty, unwashed, and smelly feet — strange, right?). Then you can sit on the benches near the FCC. The coordinator will be nearby and can give you an estimate of the waiting time.
During mealtime, the FCC is closed. If you are unable to get your feet treated before dinner, make sure to be back at the benches as soon as possible after eating.