text: why are cold sores, cold sores?   herpes simplex type 1, infects its host permanently, "hibernating" in the trigeminal ganglion (a collection of nerve cells near the ear) between outbreaks. from there, it tends to recur on the lower lip or face. for many people outbreaks are being caused by stress. getting a cold is a physical stress, and for a good many people this is when their sore appears - hence the name "cold sore". hope this helps.