Prevention:

Avoid direct contact with cold sores or other herpes lesions. Minimize the risk of indirect spread by thoroughly washing items in hot (preferably boiling) water before re-use. Do not share items with an infected person, especially when herpes lesions are active. Avoid precipitating causes (especially sun exposure) if prone to oral herpes.

Avoid performing oral sex when you have active herpes lesions on or near your mouth and avoid passive oral sex with someone who has active oral or genital herpes lesions. Condoms can help reduce, but do not entirely eliminate, the risk of transmission via oral or genital sex with an infected person.

Unfortunately, both oral and genital herpes viruses can sometimes be transmitted even when the person does not have active lesions.