Kit when retiring from NHS, eg, it’s arranged to cover doctor (10)

'kit' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe you can see a link between them that I can't see?

'retiring from nhs eg it's arranged to cover doctor' is the wordplay.
I cannot quite see how this works, but
'it's' could be 'es' ('e' can mean 'electronic' which is similar to 'IT') and 'es' is found in the answer.
'doctor' could be 'dr' (abbreviation) and 'dr' is found in the answer.
The remaining letters 'nights' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).

'when' acts as a link.

Can you help me to learn more?