Blow on the foot for warmth (4)
I believe the answer is:
sock
This clue could be a double definition.
'blow on' is the first definition.
'sock' can be an answer for 'blow' (I have seen 'Hard blow ' mean 'sock' so perhaps 'blow' could also mean 'sock'). I am not sure about the 'on' bit.
'foot for warmth' is the second definition.
The answer and definition can be both man-made objects as well as being singular nouns.
I also know that 'foot' relates to this answer.
'the' acts as a link.
Can you help me to learn more?
(Other definitions for sock that I've seen before include "Item of clothing" , "Article to cover extremity" , "Foot covering" , "Hit hard; woollen item" , "Foot-covering" .)