No air con to refresh royal ceremony (10)
I believe the answer is:
coronation
'royal ceremony' is the definition.
(I've seen this in another clue)
'no air con to refresh' is the wordplay.
'refresh' is an anagram indicator (I've seen 'refreshed' mean this).
'no'+'air'+'con'+'to'='noairconto'
'noairconto' with letters rearranged gives 'CORONATION'.
(Other definitions for coronation that I've seen before include "State occasion" , "Ceremony of installing a monarch" , "Crowning" , "Enthronement" , "Royal ceremony of 1953" .)