High temporal and spatial resolution measurements of impurity dynamics associated with an edge-localized mode (ELM) indicate that the ELM perturbation consists of two distinct parts: a rapid (< 300 micros) expulsion of impurity density at the time of the instability followed by a slower time scale (< 1 ms) decrease in the ion temperature. While the density perturbation remains nearly constant over a wide range of plasma collisionality, the temperature perturbation decreases as the collisionality increases. Analysis of the radial electric field E(r) evolution indicates that the E(r) well normally present in H-mode plasmas is modified strongly by the ELM and that the size of the temperature perturbation is correlated with the associated change in the E x B shear.