Everybody oppressed by hot room (4)

I believe the answer is:
hall
'room' is the definition.
(hall is a kind of room)
'everybody oppressed by hot' is the wordplay.
I cannot quite see how this works, but
'everybody' could be 'all' (all people) and 'all' is located in the answer.
'hot' could be 'h' (abbreviation eg on taps) and 'h' is found within the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for hall that I've seen before include "Entrance area" , "See 21" , "Large house (linked to Dotheboys, Wildfell and Toad)" , "Vestibule, lobby" , "Chamber" .)
