LIKE A DRIVER with one foot on the accelerator and the other on the brake, Tunnell et al1 in this issue of the ARCHIVES explore aggressive pulsed dye laser treatment combined with aggressive skin cooling. Cryogen spray cooling (CSC) with a burst of 鈭�30掳C liquid applied just before arrival of a laser pulse has been clearly shown to reduce the pain and risk of epidermal injury from pulsed dye laser treatment. Can very aggressive CSC protect against thermal injury from very aggressive laser treatment? The answer appears to be yes, but to a limited degree for pigmented skin and with the caveat that this study is limited to histologic observations made immediately after treatment in normal skin. For darkly pigmented skin (phototypes V and VI), there was little or no epidermal protection by aggressive CSC. But more important, the study raises important clinical issues.