Hot air added to temperature above station (10)
I believe the answer is:
paddington
'station' is the definition.
(train station in London)
'hot air added to temperature above' is the wordplay.
'hot air' becomes 'padding' (hot air can mean filler or padding).
'added to' is a charade indicator (letters next to each other).
'temperature' becomes 't' (abbreviation).
'above' becomes 'on' (above can mean on top of).
'padding'+'t'+'on'='PADDINGTON'
(Other definitions for paddington that I've seen before include "London rail terminus" , "A figure child might want for Play" , "London station - famous bear" .)