Most blisters caused by friction or minor burns do not require a doctor’s care. New skin will form underneath the affected area and the fluid is simply absorbed. Do not puncture a blister unless it is large, painful, or likely to be further irritated. The fluid-filled blister keeps the underlying skin clean, which prevents infection and promotes healing. But if you need to pop a blister: Use a sterilized needle or razor blade (to sterilize it, put the point or edge in a flame until it is red hot, or rinse it in alcohol). Wash your hands and the area thoroughly, then make a small hole and gently squeeze out the clear fluid.