Some 6 outlets smell certainly hot inside concessions (9)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

BO (abbreviation for body odour = smell) + OK (certainly = an expression of assent), then H (abbreviation for hot) inside SOPS (concessions = things given to appease someone). Oxfam (6d) has a range of charity shops, many of which are specialist second-hand bookshops.