One ironing negligently? It’s a hot day! (8)
I believe the answer is:
scorcher
'hot day' is the definition.
(I've seen this in another clue)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for scorcher that I've seen before include "something remarkable" , "burner" , "for example, really fine" , "Brand, perhaps" , "Very hot day; remarkable thing" .)