It's ice on the peak, you fool! (9)
I believe the answer is:
'you fool' is the definition.
'blockhead' can be an answer for 'fool' (I've seen this in another clue). I am not sure about the 'you' bit.
'it's ice on the peak' is the wordplay.
'it's ice on' becomes 'block' (I can't justify this - if you can you should give a lot more credence to this answer).
'the peak' becomes 'head' (head is a kind of peak).
Can you help me to learn more?
(Other definitions for blockhead that I've seen before include "Stupid person" , "Dolt" .)