That shows it’s cold and I am about to go out (4)
I believe the answer is:
rime
'that shows it's cold' is the definition.
I can't tell whether this definition defines the answer.
'i am about to go out' is the wordplay.
'i am' becomes 'I'm' (contraction).
'about to go' becomes 're' (I've seen this in other clues).
'out' is an insertion indicator.
'im' going within 're' is 'RIME'.
'and' acts as a link.
Can you help me to learn more?
(Other definitions for rime that I've seen before include "Type of frost" , "Kind of frost in mire" , "Ancient Mariner produced?" , "dated poetry" , "Hoar frost" .)