expression
please take care of yourself; please look after yourself
A set phrase used to express concern for someone's health and well-being, often in letters, emails, or when parting. It can also imply 'please be careful not to overdo it'.
寒くなってきましたので、どうぞご自愛ください。
It's getting cold, so please take care of yourself.
お忙しいとは思いますが、ご自愛ください。
I know you're busy, but please look after yourself.
Combination of the honorific prefix ご (御), the noun 自愛 (self-care, taking care of oneself), and the polite imperative ください (please). The phrase literally means 'please take care of yourself'.