Picture of Blisters
Improperly fitting shoes or shoes that are too tight cause blisters. Blisters may become infected. It is important to not pop blisters if they develop. Intact skin helps guard against infection. Use antibacterial cream on a blister and cover it with a bandage to help prevent infection.
Text Reference: Sports Medicine, vol. 20, 1995: "Friction Blisters. Pathophysiology, Prevention and Treatment"