Shoot, I've rested on two dozen summits in the Whites and there is no impact at all. Laying on a flat, hard ledge for a bit is the least amount of impact anyone could do. I'm not on a cleared area where someone has deemed it OK to put a hut, shelter, or tent platform. I haven't hacked any trees or flattened any turf. There are times when I take my break off the trail in the woods, and in those instances my higher-impact rest will be well off the trail.