The most common and most likely answer to this crossword clue is the 3 letter word TOG
I've seen this crossword clue in The Times
T
O
G
Buddy explains!
The straight part
We know that "measure of warmth" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case measure of warmth = tog.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does TOG mean?
TOG noun- A cloak.
- A coat.
- A unit of thermal resistance, being ten times the temperature difference (in °C) between the two surfaces of a material when the flow of heat is equal to one watt per square metre
- To dress (often with up or out).
- At the same time, in the same place; in close association or proximity.
- Into one place; into a single thing; combined.
- In a relationship or partnership, for example a business relationship or a romantic partnership.
- Without intermission or interruption; continuously; uninterruptedly.