On a roll (6)
(Another definition for redhot that I've seen is " Poker tip may be".)
'on a roll' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for hot that I've seen before include "Radioactive; very warm" , "Sultry or angry" , "(Of goods) stolen (colloq.)" , "Under the collar, it means anger" , "Angry or very warm" .)