apparently 'cave' can be used in several contexts
In SJLD's example: a warning not to do something (don't give him penicillin)
In Josephine's example: a warning something could be the case (and this [something could be case or something could happen] is the sense in which I come across 'cave' in my Dutch into English translations of clinical reports as part of a clinical trial)
And in this summary for medical students it is used in three different contexts:
Cave: bij anemie kan nauwelijks cyanose optreden!
a warning to remember a fact
Cave: controle nierfunctie en natrium/kalium-gehalte.
a warning to do something
Cave: hyperkaliëmie (vooral combinatie ACE-remmer + kaliumsparend diureticum!).
a warning that something can happen
http://studenten.samenvattingen.com/documenten/show/1409804/
I think the best thing to do is to let the translation depend on the context, the audience, etc.
In the first place because 'cave' implies different things in different contexts and I am not sure if the reader would understand the message correctly if you would simply translate 'cave' as 'cave' in all contexts
experts would perhaps