HowStuffWorks does not recommend popping a fever blister, or cold sore, as doing so allows the liquid inside to spread the virus. There are many steps to take that encourage healing of a fever blister.
HowStuffWorks explains that many over-the-counter topical medications treat fever blisters. Anesthetics, such as lidocaine and benzocaine, control pain. Prescription anti-viral drugs encourage the healing process.
HowStuffWorks also identifies some home remedies that lessen the impact of fever blisters. Warm or cold compresses help the area feel more comfortable. The site advises discarding one's old toothbrush and using a new one when a fever blister develops to minimize exposure to the virus. After the blister has completely healed, this toothbrush needs to be discarded as well in favor of another new toothbrush. This makes it less likely that new blisters develop.