Grew silent becoming too hot to talk (10)

I believe the answer is:

sweltering

I'm a little stuck... Click here to teach me more about this clue!

'too hot to talk' is the definition.
I can't tell whether this defines the answer.

'grew silent becoming' is the wordplay.
'becoming' indicates anagramming the letters.
'grew'+'silent'='grewsilent'
'grewsilent' is an anagram of 'SWELTERING'.

Can you help me to learn more?

(Other definitions for sweltering that I've seen before include "hot and sweaty" , "getting unpleasantly hot" , "getting uncomfortably hot" , "Hot and humid" .)

I've seen this clue in The Globe and Mail.

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