Hot spot (4)
'hot spot' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for oven that I've seen before include "Chamber for baking" , "Cooking device" , "Cooking appliance" , "Kiln, perhaps" , "Furnace, kiln" .)
(Other definitions for hell that I've seen before include "Abode of the forces of evil" , "Place of torment" , "Hades, the netherworld" , "Realm of eternal suffering" , "Infernal place" .)