If the sores are evident, they will definitely be at risk of getting them. The virus can be transferred to any part of the body if a cold sore is evident, so it is important to avoid kissing or things like oral sex if a cold sore has broken out.
It is also possible to catch the virus even if a cold sore is not visible. Sometimes someone might have some of the signs or symptoms of a cold sore coming on, an itching sensation or some tenderness prior to the actual sore appearing. This also means that the virus is present so it is good to be cautious then as well.