Frostbite, if the freezing duration is long, the local tissues will become more hypoxic and the cells will be severely damaged. At this point, local blisters, ruptures, erosion, and ulcers may occur. To quickly form a scab at this time, we should operate as follows: first, keep the local area as dry as possible; second, use astringent, drying, and anti-inflammatory ointments on the ruptured areas, such as boric acid ointment, boric acid zinc oxide menthol ointment, erythromycin ointment, mupirocin ointment, etc.