That little bit of rubbing at your heel rarely improves by ignoring it.
If you notice a hotspot on a walk, stop early. Take your boot off, shake out any grit and check whether your sock has bunched or twisted. Smooth it flat, then retie your laces so your foot feels secure without being squeezed.
Before a longer route, choose socks that sit comfortably inside your footwear and test the combination on a shorter walk. A spare pair can be useful if the first becomes soaked, but keep it dry in your pack.
Don't try to walk through persistent friction just to reach the next stop. A minute spent sorting the fit now is better than miles of distraction later.
Field tip: The first rub is your cue to adjust, not to push on.