Press release on fever in capital (6)
I believe the answer is:
prague
'capital' is the definition.
(Prague is an example)
'press release on fever' is the wordplay.
'press release' becomes 'pr' (public relations).
'on' is a charade indicator (letters next to each other).
'fever' becomes 'ague' (I've seen this in other clues).
'pr'+'ague'='PRAGUE'
'in' acts as a link.
(Other definitions for prague that I've seen before include "Gear up for this European city" , "Rather quiet" , "Capital city of Czech Republic" , "Czech Republic's capital" , "European capital" .)