boston.com — LOWELL -- Fifteen-year-old Rachel Wilk of Tewksbury was hiking in Chesterfield, N.H., last month when a fellow camper sprained her ankle. As darkness fell, a counselor had to bring flashlights to the injured girl and the campers who had stayed by her side. Then the counselor had to carry the girl, while awkwardly maneuvering a flashlight of her own